FAQ

CommFront products are designed and manufactured according to the ISO 9001:2015 standards, with surface mount technology (SMT) and lead free RoHS compliant components. Most of our products are industrial grade which require rugged components and reliability-engineering designs for environmental factors, reliability, and durability; therefore, they are much more durable than other converters available on the market. Furthermore, as part of our ISO 9001:2015 quality management program, CommFront products are strictly certified by SGS / TUV - the world's leading inspection, testing, and certification companies. We also back our high-quality products with a 5-year replacement warranty and a 30-day risk-free guarantee.

Yes, CommFront is proud to be an ISO 9001:2015 certified company (strictly certified by SGS / UKAS - cert no. SG12/04213, click here to verify), and it has developed a strict quality assurance system for its products and customer satisfaction. We are proud to provide our credentials to help our customers make a well-informed decision when choosing a long-term business partner.

The market includes many certifying laboratories. From small-scale to large-scale and non-reputable to reputable, every certifying laboratory serves its own customer base. SGS and TUV are the Nationally Recognized Testing Laboratories (NRTLs) in North America (approved by the Occupational Safety & Health Administration [OSHA]) and the Notified Bodies in the European Union, the most meticulous and recognized certifying labs in the industry. This makes our products worry and hassle free for safety and compatibility, as well as for interfacing with mission-critical and expensive equipment. Read more »

For U.S. orders, we ship our products from Maryland; for international orders, we ship our products from Maryland or our office in Singapore. Orders are normally shipped within 24 business hours, and orders with express shipping are normally shipped on the same business day.

As part of our ISO 9001:2008 quality management system, we provide fast and intensive customer support through the following ways:
- Online Feedback Form (Typical response time: within minutes and 24 hours)
- Emails (24/7 with fast response)
- Live Chat (9:00 a.m. to 9:00 p.m. EST, Monday to Friday)
- Phone (9:00 a.m. to 6:00p.m. EST, Monday to Friday)

We provide 5-year replacement warranty. Within 5 years from the time of purchase ("Warranty Period"), if a rare malfunction should occur, CommFront will, without charge, repair or provide a replacement for any product that proves to be defective in materials or workmanship. Simply complete the RMA form and send it to us by email, and we will allocate an RMA number for your return and replacement. Replacement will typically be shipped within 1 to 3 business days upon receipt of your return.

Not just the United States, we ship our products worldwide with tracking. Given the availability of items ordered, U.S. orders are normally shipped on the same day or the next business day, with an ETA of 2 to 3 business days using USPS Priority. Also, given the availability of items ordered, international orders are normally shipped the same day or the next business day, with an ETA of 7 to 14 Business Days by using Global Priority or Registered Airmail. Moreover, for orders that are above $300 (non-discounted orders), we provide FREE Express shipping!

Please note that the cut-off time for our express shipping is 5:30pm EST.

You may return products sold by us within 30 days of purchase for a full refund (minus shipping charges) by the same method in which payment was received. Please complete and send us the RMA form and we will send you the RMA number for your return and refund. You can expect a refund in the same form of payment originally used for the purchase 1 to 3 business days after we have received your return.

CommFront respects and cares for your rights of privacy. We use the information you provide about yourself only to complete your orders or answer your questions; in some rare cases, we might use your email address for important updates. We do not share this information with outside parties except to the extent necessary to complete that order. To prevent unauthorized access, maintain data accuracy, and ensure the correct use of information, CommFront has put in place appropriate physical, electronic, and managerial procedures to safeguard and secure the information we collect online and offline.

The entire CommFront website is secured by the latest TLS (Transport Layer Security) encryption. TLS is the latest standard security technology for establishing an encrypted link between a web server and a browser. This link ensures that all data passed between our web server and your browsers remain secure, private, and integral. In addition, CommFront website is certified Level 1 PCI DSS compliant.

What is PCI DSS Compliance?
The Payment Card Industry Data Security Standard (PCI DSS) is an information security standard for organizations that handle credit card and debit card information. Defined by the Payment Card Industry Security Standards Council, the standard was created to increase controls around credit card data to reduce credit card fraud via its exposure. If any vendor wants to sell online and accept payments from Visa, MasterCard, American Express or Discover credit cards, the software and hosting needs to be PCI compliant. For more information, please visit our Privacy Policy.

The HTS code for our products is 8471.80.1000

The ECCN code for our products is 4A994.a

We accept ALL major credit cards, PayPal, and bank transfer. Please note that currently we accept only Visa and Master for credit card payment, if you wish to pay by AMEX, please check out with PayPal payment gateway. For bank transfer, please contact us and request for a Proforma Invoice. Please also note that for credit card payment, some issuing banks may impose a charge of International Transaction Fee (about 0.8%), contact us if you have any doubts, thank you!

Just as there are many differences between industrial- and commercial-grade computers, the industrial- and commercial-grade converters differ in many ways, such as the level of circuit protection, temperature range and noise tolerance. Most importantly, true industrial-grade converters require rugged components and reliability-engineering designs for environmental factors, reliability, and durability, therefore, they are much more durable than commercial-grade converters. Industrial-grade converters are designed to interface with mission-critical equipment, such as computers, PLC, SCADA and HMI - whether in the field, server room, factory, control room, or fire command center. Visit the wikipedia's pages for more information on: Temperature classifications and Reliability engineering.

The RS232 data line has a distance limitation of fifty (50) feet (about 15 m), while the RS485/RS422 can go up to 4000 feet (1200 m). It is a common practice to use converters to extend the RS-232 data line. There are 3 ways to extend the distance of your RS232 devices: Convert to 2-wire RS485, convert to 4-wire RS422 or use our isolated RS232 repeaters. To protect your RS232 devices from surge voltages while extending the RS232 distance, we would recommend the RPT-232-3 - an optically isolated RS232 data repeater (extender) (TX, RX, and GND), which works in pairs to extend the full-duplex RS232 distance up to 1.8 miles (3 km) @ 300bps baud or 1600 feet (500m) @ 28.8kbps baud. This product features opto-isolation circuitry, which effectively protect your RS-232 devices from ground loops, transient surges, lightning and spikes.

DTE stands for Data Terminal Equipment, a PC is a DTE. DCE stands for Data Communication Equipment, a Modem is a DCE. DTE normally comes with a Male Connector, while DCE comes with a Female Connector, but that is not always the case. Use the guide below as a simple way to confirm: Measure Pin 3 and Pin 5 (DB9 Connector) with a multi-meter. If you get a voltage of -3V to -15V, it is a DTE device. If the voltage is on Pin 2, then it is a DCE device. Note: The result for the DB-25 Connector is reversed, and Ground for the DB-25 is on Pin 7.

To learn more about RS232, check out:
RS232 basics: Three easy steps to understand and control your RS232 devices

Handshake Lines are used to control the direction of data flow between DTE and DCE. They are:
RTS (Request to Send) - Asserted by DTE to prepare DCE to receive data.
CTS (Clear to Send) - RTS Acknowledgment by DCE to allow DTE to transmit.
DTR (Data Terminal Ready) - Asserted by DTE to indicate that it is ready to be connected.
DSR (Data Set Ready) - Indicates an active connection by DCE.
DCD (Data Carrier Ready) - Used by modem when a connection has been established with remote equipment.
RI (Ring Indicator) - Used by the modem to indicate a ring signal from telephone line.

To learn more about RS232, check out:
RS232 basics: Three easy steps to understand and control your RS232 devices

This is not necessary. The converters come with the Auto-Turnaround feature, the RS-485 transceiver circuit will change the data direction automatically upon sensing a ""start bit"" (a logic high ""Mark"" to low ""Space"" transition) from its RS232 data transmit line (TxD) so that the RS-485 side is in ""listening"" mode, thus reducing the chance of data collusion.

Note: Auto-turnaround feature is not applicable for full-duplex communications such as RS232, RS422, and TTL, because full-duplex communications consist of two channels: TX (Transmitting) and RX (Receiving), and both channels can operate simultaneously.

Yes, to satisfy the requirements of some software, the following handshake lines are tied together in the converters.
- Pin 1 (DCD) is connected to Pin 4 (DTR) and Pin 6 (DCR).
- Pin 7 (RTS) is connected to Pin 8 (CTS).
Note: Above pin assignments are for DTE devices.

Our port-powered converters derive power from the RS232 port. The converters extract power from the TX line using a capacitor charge pump, and do NOT require any handshake signal (e.g. DTR or RTS). Also, it is not necessary for there to be continuous data to power the converter.

The main purpose for the +5V sign on the termination board is for port power measurement, if you doubt that the converter is not functioning, measure this pin and the Gnd with a Volt meter. If you get a signal of more than +5V, your converters are powered correctly, otherwise please check your connection or use an external 5VDC regulated power supply if the port power is insufficient. Note: If the converter is connected to is a DCE device, you need to swap Pin 2 and 3 (or use a null-modem converter to connect between the DCE device and the converter).

You can connect a maximum of 128 serial devices (RS485 or RS422) to our converters. However, this depends a great deal on a few factors such as the RS485/RS422 devices connected to the converter, data baud rate, cable distance, etc. Please refer to the converters' datasheets for more information.

A single RS485/RS422loop can go up to 4000ft (1200m) by using standard copper wire (screened twisted pair such as CAT-5e). This distance (using copper wire) can be extended to another 4000ft(1200m) by using our RS485/RS422 repeater (Model: RPT-485_422-2 and RPT-485_422-4). Note: A maximum of two repeaters can be used in series. The RS485/RS422 distance can be further extended to up to 24.8 miles (40km) by using Single-Mode Fiber Optic Cables and our Single-Mode RS232/RS485/RS422 to Fiber Optic Media converter (Model: FBR-Serial-2).

RS485/RS422 is a network in a linear, multi-drop configuration; however, star-wiring is inevitable in some places. Our RS485/RS422 Hubs/Splitters (Model: HUB-485-4 and HUB-Serial-4) split an RS485/RS422 network into four, thus making star-wiring possible.

Screened twisted-pair cable (e.g. CAT-5e) is recommended to prevent external noises induced to the RS485/RS422 busses.

RS485/RS422 network is normally used over a long distance and in an electrically noisy environment, noises, reflections, and data errors might occur if there is no termination on the RS485/RS422 buses. Both ends of the transmission lines should be terminated to reduce noises and reflections that can cause data errors. There are several methods of terminating data lines, and we recommend parallel termination. Instead of using pull-up or pull-down resistors, the parallel 120-Ohm end-of-line terminators provide a hassle-free and effective way of termination. However, since the Terminator will increase the load on the data circuit, we recommend to turn ON the Terminator only when the data rate is over 19.2kbps or the distance exceeds 660 feet (200m).

Depending on the power from RS232 port, the RS232/RS485/RS422 converters can go up to 4000 feet (1200 m) for the maximum baud rate of 19200 bps. Distance can be extended by using RS485/RS422 repeaters or fiber optic converters. Fiber Optic converters can go up to 24.8 miles (40km).

The maximum number of supported nodes in a RS485/RS422 network depends on the RS485/RS422 master, for example, if the RS485 master supports only 32 nodes, the maximum number of supported nodes in the RS485 network is 32. The use of RPT-485_422-2 and RPT-485_422-4 only extends the RS485/RS422 distance, it will not affect the total number of nodes that can be used in the network.

If you are using our port-powered converters with the provided terminal blocks, the 120-ohm terminator is set through a simple jumper setting (marked as ""120"" for CVT-485-x and ""J4"" for CVT-485_422-x or CVT-422-x). Terminate the jumper to turn ON the terminator and remove it to turn the terminator OFF. If you are using our port-powered converters without the provided terminal blocks, short pin 6 & 7 for CVT-485-x or pin 4 & 8 for CVT-485_422-x / CVT-422-x on the DB-9 connectors (RS-485/422 side) to turn ON the terminator.

For CVT-485_422-4, tie J3 & J4 to turn ON the terminator for RS485; tie J1 & J2 to turn ON the terminator for RS422.

Yes, the HUB-485-4 supports 1 master (input) and 2 to 4 slaves (outputs) OR 1 slave (input) and 2 to 4 masters (outputs).

Yes, the HUB-485-4 works at physical layer and it supports high-level protocols such as Modbus and BACnet MS/TP, etc.

No, this is not necessary if only one HUB-485-4 is used. However, if multiple HUB-485-4 are connected and configured as a RS485 bus, then end-of-line 120-Ohm terminators are required at both ends of the bus.

Yes, by connecting the input of the 2nd HUB-485-4 to one of the outputs of the 1st HUB-485-4, 2 HUB-485-4 can be cascaded and become a 1-input/7-output hub.

Yes, connecting multiple HUB-485-4 together can daramatically increase the system's flexibility and reliability. Please refer to the datasheet for more information.

Opto-isolation uses optical isolators to isolate two serial devices. Optical isolator is a common element used for RS232, RS485 and RS422 systems. With an optical isolator, only light passes between two serial devices, this is performed with an LED and a photosensitive transistor. There are many benefits of using opto-isolated converters, most importantly, it protects your RS232 devices from transient surges, lightning and spikes. Optical isolation also eliminates ground loop and noise problems because the ground of two connected devices are separated.

The Static Protection Circuit is also called an ESD (Electro-Static Discharge). The charged capacitance of a human body enables a person to destroy integrated circuits with a single touch. Such a contact can easily occur during the installation of an interface cable. To prevent ESD damage, our converters come with the protection circuit to protect against ESD levels for up to ±15kV. Static Protection Circuit is NOT an Opto-Isolator. To prevent your PC or serial devices from being damaged by ground loops, transient surges, lightning and spikes, opto-isolated converters (i.e. CVT-485-3, CVT-485_422-3) or isolators (i.e. CVT-232A-3 or CVT-232B-3) are required.

Auto-turnaround is applicable for 2-wire half-duplex RS485 communication. Upon sensing a "start bit" (a logic high "Mark" to low "Space" transition) from its RS232 data transmit line (TxD), the RS-485 transceiver circuit will change the data direction automatically so that the RS-485 side is at the "listening" mode, thus reducing the chance of data collusion. Auto-turnaround feature is very useful for half-duplex RS485 communications, however, it is not applicable for full-duplex communications such as RS-232, RS-422 and TTL because both of the TX and RX channels are operating simultaneously.

Balanced signaling (also named as Differential signaling) is used for RS485, RS422, USB and Ethernet, it is a method of transmitting data by means of two complementary signals sent on two separate wires. The receiving device reads the difference between the two signals and ignores the wires' voltages with respect to ground, therefore, the signal can be transmitted much longer than its opposite technique: Unbalanced signaling. Unbalanced signaling (also named as Single-Ended signaling) is used for RS232 and TTL, the transmitter generates a single voltage that the receiver compares with a fixed reference voltage, both relative to a common ground connection shared by both ends. Unbalanced signaling can not run over a long distance and might have ground loop and noise problems.

SMT stands for Surface Mount Technology. Our converters use SMT circuits, thus the current consumption is very small (less than 10mA), while other Discrete Component type of converters on the market consume much more power - normally between 50mA to 100mA. Less current generates less heat, hence, the converters last longer.

GND on the converters is the Signal Ground. Do NOT connect GND to the Earth.

No problem. For your convenience, we provide a terminal block with each converter, which is useful as you can connect the RS-485/RS-422 cables directly into the terminal block without making your own connector. You can also use the converters without the terminal block, as it is merely a conversion from DB9 to Screw Terminals, with some jumpers on the circuit board. In case you need to make you own connections without using the terminal block, please refer to the Pin Assignment on the datasheet for detailed connections.

This is not necessary, all of our converters can auto-detect and self-adjust to the data format (baud rate, data bit, parity, stop bit, etc.) used by the serial devices. The baud rate, data bit, parity, stop bit etc must be consistent on the master and slave devices on a higher protocol level.

Yes, all of our converters are hot-pluggable. They are equipped with Data Transceiver Protection Circuitry to protect the devices from voltage and current surges.

Our port powered converters consume less than 10mA of current. Our externally powered converters consume less than 30mA of current, which is about 3 Watts.

Yes, our port-powered converters work well with new computers that come with the RS232 ports, which normally come with a minimum of +/-5VDC port power. However, please note that most of modern computers (especially laptops) do NOT come with RS232 COM ports, therefore USB to RS232 cables / converters (which creates a Virtual COM port on the PC) are widely used.

We have tested our converters with many kinds of USB to RS-232 cables / converters available on the market. There is no problem using our converters with USB to RS-232 cables / converters. However, if you found your USB/RS232 converters/cables do not work with our converters, please drop us an email.

The major difference between 3-wire and 7-wire RS232 Isolators is: 3-wire isolator optically isolates three (3) RS-232 lines (TX, RX and GND), while 7-wire isolator optically isolates seven (7) RS-232 lines (TX, RX, RTS, CTS, DTR, DSR and GND).

CVT-485_422-1 and CVT-485_422-3 are dual-function converters, so they can be used to convert any standard RS232 port into a two-wire balanced half-duplex RS485 port, or a four-wire balanced full-duplex RS485/RS422 port and vice versa. This is done through the Jumper settings on the terminal block. For example: Jumper 1, 2 & 3 are ON (shorted) by default, which is used for RS232/RS485 conversion. When all three jumpers are removed (opened), it becomes a RS232/RS422 converter.

The TTL signal has a distance limitation of 10 feet (about 3 m), while the RS485/RS422 can go up to 4000 feet (1200 m). Since TTL is a full-duplex communication, we recommend to use our full-duplex RS422/TTL converter (Model: TTL-485_422-2) to extend the 5V TTL distance to up to 4000 feet (1200 m). If the distance is more than 4000 feet (1200 m), we would recommend to use our Serial to Fiber Optic Converter (FBR-Serial-2), together with the port-powered RS232 to TTL converters (TTL-232-1 or TTL33-232-1), to extend the TTL distances to up to 24 miles (40 km).

You can connect a maximum of 128 serial devices on RS485/RS422 side. However, this depends a great deal on a few factors such as the RS485/RS422 devices connected to the converter, data baud rate, cable distance, etc.

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect two RS232/RS485 converters to your PC's COM ports (if your PC does not have enough COM ports, you may use USB to RS232 converters or cables). Run two instances of 232Analyzer software on your PC. When you send commands (i.e. ""CommFront"" in ASCII format) from one COM port, you should receive the same commands on the other, and vice versa. By performing a simple Loopback Test like this, you can test you RS485 transceiver, which is very helpful when you are in doubt about the performance of your converters or cables. Note: RS232/RS485 loopback requires two RS485 converters to properly perform the test. Click here to download a FREE copy of 232Analyzer software.

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect TX+ and TX- to RX+ and RX- respectively and connect the RS232/RS422 converter to your PC's COM port. Run the 232Analyzer software and send commands (i.e. ""CommFront"" in ASCII format) from the software, you should receive an echo of the commands sent. By performing a simple Loopback Test like this, you can test both the Transmitter and Receiver of your RS232/RS422 converter, which is very helpful when you are in doubt about the performance of your converters or cables.
Click here to download a FREE copy of 232Analyzer software.

Loopback Test provides an effective way to test your RS-232 COM ports or cables. By using our 232Analyzer software, you can test both your RS-232 COM ports and cables:

If you are testing your local RS232 COM port, simply connect Pin 2 to 3 of your RS232 port, then run the 232Analyzer software and send commands from the Send_Command_Pane, you should get an echo of the commands sent.

If you are communicating with a remote RS232 device, run the 232Analyzer software on both ends of the PC and turn ON/OFF the line state or send commands from one end, and you should be able to see the changes or receive the commands on the other end. By performing a simple Loopback Test like this, you can test both the RS232 COM port and cable, which is very helpful when you have doubts about the performance of your COM ports or cables.
Click here to download a FREE copy of 232Analyzer software."

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect the female connector end of the isolator to your PC’s COM port and connect the other end (male connector) to another of your PC’s COM ports with a null-modem converter (or connect pin 2 to 3, pin 3 to 2, and pin 5 to 5 between the male connector and your PC's RS232 connector).

Run two instances of 232Analyzer software on your PC. When you send commands (i.e. ""CommFront"" in ASCII format) from one COM port, you should receive the same commands on the other, and vice versa. By performing a simple loopback test like this, you can test both the transmitter and receiver of the isolator. This is very helpful when you are in doubt about the performance of your isolator.
Click here to download a FREE copy of 232Analyzer software.

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect TX (TTL Out) to RX (TTL In), and then send commands from the 232Analyzer software. You should get an echo of the commands sent. By performing a simple Loopback test like this, you can test both the Transmitter and Receiver of the RS232/TTL converter. This is very helpful when you are in doubt about the performance of your converters or cables.
Click here to download a FREE copy of 232Analyzer software.

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect two RS485/TTL converters to your PC's COM ports (if your PC does not have enough COM ports, you may use USB to RS232 converters or cables). Run two instances of 232Analyzer software on your PC. When you send commands (i.e. ""CommFront"" in ASCII format) from one COM port, you should receive the same commands on the other, and vice versa. By performing a simple loopback test like this, you can test both the transmitter and receiver of the converter. This is very helpful when you are in doubt about the performance of your converters or cables.
Click here to download a FREE copy of 232Analyzer software.

Performing a Loopback Test is easy with our 232Analyzer software. Simply connect your PC's RS422 port to the RS422 side and short TX and RX on the TTL side, and then send commands from the 232Analyzer software. You should get an echo of the commands sent. By performing a simple Loopback test like this, you can test both the Transmitter and Receiver of the RS422/TTL converter. This is very helpful when you are in doubt about the performance of your converters or cables.
Click here to download a FREE copy of 232Analyzer software.

Yes, all of our USB products are Windows 10, Windows 8 and Windows 7 compatible, and the latest Mac and Linux OS are also supported.

1. Drivers are included on the CD supplied with the USB-Serial adapter. Insert the CD into the drive. Note: For Windows Vista, please disconnect your PC from the Internet before installing drivers; otherwise, Windows Vista will search for and install the drivers automatically from Windows Updates and cause errors.

2. Connect the USB-232-1 or USB-232A-1 to an available USB port, and the ""Found New Hardware Wizard"" will guide you through the installation process. Note: When prompted to connect to Windows Updates to search for drivers, select ""No, not at this time"" and follow the instructions for installing from the CD.

3. If it is the first time you install the driver for CommFront’s USB to Serial device, you will need to install the driver twice. One is for the “USB Serial Converter”, and the other one is for the “USB Serial Port”. Note: Do NOT close the 2nd “Found New Hardware Wizard” window while installing the driver.

For USB-232-1 and USB-232A-1, you can download the latest drivers (chipset: FT232B) for CE6.0 or other OS from FTDI's website:http://www.ftdichip.com/Drivers/VCP.htm.

For USB-Serial-3, you can download the latest drivers (chipset: CP210x) from Silicon Labs' website:http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx.

Open the ""Device Manager"" and make sure the USB-Serial adapter(s) show under ""Ports (COM & LPT)"" and ""Universal Serial Bus Controllers"". Also, make sure there is no yellow exclamation icon over the two items.

Perform a loopback test by using our 232Analyzer software to ensure that the COM port(s) are functioning correctly.

Yes, the two RS232 channels of the USB-232A-1 adapter can be operated simultaneously, which provides a perfect match for the full-duplex monitor cable (CBL-Full-1A) used in the 232Analyzer software.

Note: to improve the accuracy of the 232Analyzer's timestamps, change the latency timer to 1 msec. Please refer to the topic of ""How do I change the latency timer of the USB products"" below for details.

To change the COM port number(s), please follow these steps:
1. Open the Windows Device Manager (under ""Control Panel\System\Hardware"").
2. Right-click on the COM port you want to change (under ""Ports (COM & LPT)"").
3. Left-click on ""Properties"".
4. Click on the ""Port Settings"" tab.
5. Click on the ""Advanced..."" button.
6. Use the drop-down list to select the COM port number you want to use.
7. Click ""OK"".
8. Click ""OK"" again and close the Device Manager.

To change the latency timers (response time) for the USB products, follow the instructions below:
1. Open the Windows Device Manager (under ""Control Panel\System\Hardware"").
2. Right-click on the COM port you want to change (under ""Ports (COM & LPT)"").
3. Left-click on ""Properties"".
4. Click on the ""Port Settings"" tab.
5. Click on the ""Advanced..."" button.
6. Under the ""BM options"", select the desired latency timer from the drop-down list, it ranges from 1 to 255 msec (default: 16 msec).
Note: to improve the accuracy of the 232Analyzer's timestamps, change the latency timer to 1 msec.

Yes, our USB products support custom baud rates, such as 76.8kbps. However, some parameters need to be changed, the user manual is available here. Note: the chipset used for our products is FT232B.

Performing a Loopback Test is easy with our 232Analyzer software (included on the CD supplied with the adapter). Simply connect pins 2 and 3 of the DB-9 connector (RX to TX) and run the program. Then send commands from the software, you should receive an echo of the commands sent. By performing a simple loopback test like this, you can test both the transmitter and the receiver of the adapter. This is very helpful when you are in doubt about the performance of your USB-RS232 adapter.
Click here to download a FREE copy of 232Analyzer software.

Performing a Loopback Test is easy with our 232Analyzer software (included on the CD supplied with the adapter). Simply connect a USB-Serial-3 converter to your USB port, tie pin TX and RX, and then send a command from the 232Analyzer software. You should receive an echo of the command sent. By performing a simple loopback test like this, you can test both the transmitter and receiver of the converter. This is very helpful when you are in doubt about the performance of your converter.
Click here to download a FREE copy of 232Analyzer software.

In its simplest terms, fiber optics is a medium for carrying information from one point to another in the form of light. Unlike the copper wire mode of transmission, fiber optics is not electrical in nature.

Fiber optic systems run on light-speed fiber backbone which inherently resistant to radio and electrical interference, such as EMI/RFI, lightning, transient surges and ground loops, therefore, they have the following advantages over copper wire systems:
- Speed: Fiber optic systems operate at high speeds - up to gigabits.
- Bandwidth: Fiber optic systems have large carrying capacity because light sources are used for transmission.
- Distance: Signals can be transmitted much farther without needing to be regenerated or strengthened.
- Resistance: Fiber lines are inherently resistant to EMI/RFI, lightning, transient surges and ground loops; therefore, they are ideal for data communications surrounded by heavy electrical or radio interference.

Fiber optic systems are used for transmitting information over long distances. For example, RS-232 has a distance limitation of 50 ft (15m). Some projects require the RS-232 data to be sent over long distances, if it is transmitted within 4000 ft (1.2km), then you can probably use a pair of RS-232 data repeaters (such as CommFront's RPT-232-3). However, if the distance is over 4000 ft (1.2km), then a fiber optic system is recommended.

Fiber optic systems are also used for transmitting information over large areas. For example, a factory automation system often covers a number of buildings or areas. With the CommFront's advanced multi-drop fiber optic converter (FBR(M)-Serial-2), different RS-485/RS-422 systems located in different areas can now be combined together.

A typical fiber optic system consists of a transmitting device, which generates the light signal; an optical fiber cable (one or two cores for transmitting and receiving), which carries the light; and a receiver, which accepts the light signal that is being transmitted. The fiber itself is passive and does not contain any active, generative properties. For CommFront products, the transmitting and receiving devices are built within the same device. Sometimes we call it a Fiber Optic Converter or Fiber Optic Transceiver.

Yes. The CommFront's multi-drop fiber optic converter (FBR(M)-Serial-2) supports up to 255 fiber nodes, and depends on the site situation, it can be configured as a daisy-chain or a self-healing/redundant ring fiber network. When configured as a ring fiber network, the built-in self-healing feature allows the data to be transmitted clockwise or counterclockwise; therefore, failure of any individual converter will not affect other devices located on the same fiber ring, making the entire data network more robust and reliable. The unit also features redundant power supplies and power alarm outputs for uninterrupted system performance and easy maintenance. The FBR(M)-Serial-2 overcomes the limitations of conventional point-to-point fiber network and dramatically expands the serial data network in terms of distance, flexibility, and reliability.

Two basic types of fiber and many different types of fiber optic cables are used today. The two types of fiber are called Single-Mode (SM) and Multi-Mode (MM). SM fiber is more expensive, but more efficient than MM fiber, SM fiber is generally used in situations in which the distances to be covered are greater. SM fiber is a single strand of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. SM fiber comes with a relatively narrow diameter; the small core and single light wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type. The typical distances for SM fiber are 6.2 miles (10 km) to 62 miles (100 km).

Multi-Mode fiber is a multi-strand of glass fiber with a diameter of 50 to 100 microns. Light waves are dispersed into numerous paths or modes, causing signal distortion at the receiving end for long distance cable runs. The typical distances for MM fiber are 0.3 miles (500m) to 3 miles (5km). Note: Fiber optic converter and fiber cable must be of the same type, e.g. SM fiber optic converter must be used together with SM fiber cable, while MM fiber optic converter must be used together with MM fiber cable.

OM1, OM2, OM3, OM4 and OM5 represent different generations of Multimode Fiber (MMF). OM1 is 62.5/125µm core diameter, while OM2, OM3, OM4 and OM5 are 50/125µm core diameter. OM2 is considered standard 50µm MMF, while OM3, OM4 and OM5 fibers are laser-optimized multimode fibers (LOMMF).

OM1: Generation 1 (phasing out); 62.5/125µm core diameter; most commonly used for Serial-Fiber and 100M Ethernet applications

OM2: Generation 2; 50/125µm core diameter; most commonly used for Serial-Fiber and 100M/1G Ethernet applications

OM3: Generation 3; 50/125µm core diameter; most commonly used for 10G Ethernet applications

OM4: Generation 4; 50/125µm core diameter; most commonly used for 40/100G Ethernet applications

OM5: Generation 5; 50/125µm core diameter; most commonly used for 40/100/200/400G Ethernet applications

Almost all Single-Mod and Multi-Mode cables are supported for CommFront fiber optic converters:
- Single-Mode: 8.3/125, 8.7/125, 9/125, 10/125µm;
- Multi-Mode: 50/125 (OM2, OM3, OM4, OM5), 62.5/125µm (OM1 - phasing out)

CommFront fiber optic converters come with the options of ST, SC, FC and LC connectors.
ST: A keyed bayonet type similar to a BNC connector; it can be inserted into and removed from a fiber optic converter quickly and easily. 
SC: A push on/pull off connector with a plastic housing and a locking tab; it is one of the earliest and most commonly used types.
FC: A connector with a threaded body which was designed for use in high-vibration environments. It is widely used with both single-mode and multi-mode fiber.
LC: A Lucent Connector (LC) that comes with a 1.25mm ferrule, half the size of a SC or ST connector. LC connectors are normally built-in with a SFP (Small-form Factor Pluggable) module.

The wavelength for CommFront's fiber optic converters is 1310nm (nanometers). Wavelength and frequency are related, 1310nm falls into the frequency range of infrared. The reason for infrared range frequency is that the attenuation of the fiber is much less there.

The CommFront's conventional point-to-point fiber optic converters (FBR-Serial-2 and FBR-Ethernet-2) work in pairs; two cores of the fiber optic cable are required, one for transmitting and one for receiving.

The CommFront's advanced multi-drop fiber optic converters (FBR(M)-Serial-2) supports up to 255 fiber nodes, and can be configured as a daisy-chain or a self-healing/redundant ring fiber network, depending on the site situation. Four cores of the fiber optic cables are required, two for port A and two for port B.

The typical maximum distance for RS232 is 50 feet (15 meters); for RS485 and RS422, it is about 4000 feet (1.2 km) by using twisted-pair copper-wire cables.

The typical maximum distance for 10/100M Ethernet is about 328 feet (100 meters) by using CAT-5e twisted pair cable.

Depending on the fiber cable and the type of converter used, a Multi-Mode fiber optic link can go up to 3 miles (5 km), while a Single-Mode fiber optic link can go up to 25 miles (40 km).

Yes. Standards can be mixed and matched, so an RS232 device can be connected to one side of the fiber link, and RS485/RS422 devices to the other; or RS485 (2-wire) devices can be connected to one side of the fiber link, and RS422 (4-wire) devices to the other, without using a converter and isolator.

For conventional point-to-point fiber optic converters (FBR-Serial-2 and FBR-Ethernet-2), there are no jumper or DIP switch settings in the unit. Simply connect the serial data into its respectively connectors and hook up the system. The FBR-Serial-2 supports data rates up to 115.2kbps and features data format auto-sensing and self-adjusting, and therefore, no DIP switches or jumpers are required. When working with RS485 signals, the CommFront’s auto-turnaround feature eliminates the need for flow control.

For advanced multi-drop fiber optic converters (FBR(M)-Serial-2), there are DIP switch settings for master/slave and 120-Ohm termination (Note: Only 1 master is allowed in a system). Other than that, there are no jumper settings in the unit. The FBR(M)-Serial-2 supports data rates up to 115.2kbps and features data format auto-sensing and self-adjusting; and when working with RS485 signals, the CommFront’s auto-turnaround feature eliminates the need for flow control.

No. There are no jumper or DIP switch settings in the unit. The FBR-Ethernet-2 is a plug and play unit featuring auto-negotiation for half or full-duplex and 10 or 100Mbps data rates. It also supports MDI (straight-through) and MDIX (crossover) cables, no DIP switches or jumper settings are required.

The FBR-Serial-2 and FBR(M)-Serial-2 support data rates up to 115.2kbps. The units feature data format auto-sensing and self-adjusting; and when working with RS-485 signals, the CommFront’s auto-turnaround feature eliminates the need for flow control.

Up to 128 RS485 or RS422 devices can be connected to the RS485/RS422 loop.

The 232Analyzer is an advanced professional serial port analyzer that allows you to control and monitor serial port activities (RS232/RS485/RS422/TTL). It is also an useful tool for troubleshooting your serial converters or data networks.

Anyone who is dealing with serial communications, including:
- Technicians
- System integrators
- Programmers
- Software developers
- Hardware engineers
- Lab experts
- IT specialists
- Others

This product can be used for:
- Troubleshooting serial converters or data networks (e.g. loopback test)
- Serial hardware development
- Serial device driver development
- Serial protocol development, implementation, or reverse-engineering
- Software testing
- Hardware testing
- COM port testing
- External serial device control and monitoring
- Others

This product can be used in all sorts of serial communication applications, including:
- Building automation
- Industrial/commercial control and automation systems
- SCADA
- PLC
- A/V control
- Security systems
- Communication systems
- Other systems or devices that use serial communications (RS-232/RS485/RS422/TTL)

Yes, 232Analyzer is extremely easy to use. Anyone who knows how to use HyperTerminal can operate the software within seconds, without any programming knowledge.

232Analyzer comes with two basic features: control (debug) and monitor serial devices. The product supports data input and monitoring in Hexadecimal, Decimal, Octal, Binary and ASCII formats. It also allows you to change / monitor RS-232's line state: RTS, DTR, CTS, DSR, DCD, and RI. All data and signal flows are logged in the Communication Logging Window, which can then be saved as .txt, .doc or .rtf files for further analysis.

232Analyzer not only allows you to control/monitor RS-232's activities, but with the right type of converters (e.g. our port-powered RS232 to RS485/RS422/TTL converters), you can also control/monitor other serial devices, such as RS485, RS422 and TTL.

232Analyzer is a professional protocol analyzer software, it is extremely easy to use yet comes with many advanced features, such as:
- Two operating modes: Debugging/simulating and monitoring (supports both half-duplex and full-duplex monitoring)
- Timestamps for the data captured in monitoring mode
- Send/receive data in all formats: Hexadecimal, Decimal, Octal, Binary, and ASCII string
- Send/receive handshake signals: RTS, DTR, CTS, DSR, DCD and RI
- COM 1 to 16
- Frequently Used Keys: 00h to 1Fh (a total of 32 numbers)
- Programmable Buttons: Send command strings, signals or data sequence with one single button (a total of 32 numbers)
- Programmable Auto-Response: Upon receiving certain data or signals, you can program automatic output data and/or signals (a total of 16 numbers)
- Programmable Macros: Send sets of data/signals and response to different types of incoming data/signals with timer and sequence (a total of 8 x 8 steps, and 8 x 8 sub-routines)
- Virtual LEDs: View the RS-232 line state and control RTS and DTR, break communication if necessary
- Data logging: All communications are logged and can be saved into .txt files for future analysis
- Checksum Calculator: AND, OR, XOR, NOT, Reverse Bit Order, +, -, x, \, MOD, CRC-16 (for Modbus), etc.
- Notation Converter: Convert data from one notation to another
- ASCII chart: All 256 ASCII codes in different formats
- Device Profile: Settings for different devices can be saved individually
- Flexible screen adjustment
- User preferences settings: Color settings, Startup Actions, Exit Actions, etc.
- Customizable colors for Background, TX, RX1 and RX2 (2nd COM port channel when using full-duplex monitoring)

Software Features FREE Version Registered Version
Timestamps (Monitoring Mode) No Yes 
Available Data Formats Dec, Oct, Bin and
ASCII Hex, Dec, Oct, Bin and ASCII
Monitoring Mode No Yes
Programmable Buttons No Yes
Programmable Auto-Response No Yes
Programmable Macros No Yes
New/Save Device Profile No Yes
Open Device Profile Yes Yes
Open/Save Log File No Yes
User Notes Yes Yes
Checksum Calculator Yes Yes
Notation Converter Yes Yes
Options Yes Yes

232Analyzer comes with more features than most of the hardware analyzers on the market. It is extremely easy to use and does not require any programming knowledge. Software activation can be done within minutes, so there is no product waiting time. Moreover, the software price is only a fraction of the hardware analyzer's. However, please note that the timestamp accuracy for hardware analyzers are generally better than software analyzers'.

232Analyzer is an advanced protocol analyzer software, it is extremely easy to use, yet comes with many advanced features that are not available in HyperTerminal or other analyzer tools. See software features…

There are four license types:
Limited License: FREE, no time limitation.
Single-Computer-License: To be installed on a single computer.
Company-Multi-License: To be installed on up to five computers within the same organization at the same physical location.
Company-Site-License: To be installed on any number of computers within the same organization at the same physical location.

The 232Analyzer supports the following baud rates:
100
300
600
1,200
2,400
4,800
9,600
14,400
19,200
28,800
56,000
576,000
115,200
128,000
256,000

The 232Analyzer supports Windows 10, 8, 7, Vista, XP, 2000 and 98. The product is fully compatible with both 32-bit and 64-bit OS.

The 232Analyer software supports COM port number 1 to 16, and to change the COM port number(s), follow these steps:
1. Open the Windows Device Manager (under ""Control Panel\System\Hardware"").
2. Right-click on the COM port you want to change (under ""Ports (COM & LPT)"").
3. Left-click on ""Properties"".
4. Click on the ""Port Settings"" tab.
5. Click on the ""Advanced..."" button.
6. Use the drop-down list to select the COM port number you want to use.
7. Click ""OK"".
8. Click ""OK"" again and close the Device Manager.

Yes, this product allows you to change/monitor the RS232's line state: RTS, DTR, CTS, DSR, DCD, and RI.

Yes, two COM ports can be opened at the same time, and with the full-duplex RS232 monitor/control cable (CBL-Full-1A), you can monitor RS232 communications with direction indication. Learn more…

Yes, by using two units of RS232/RS485 converters (e.g. CVT-485-1 or CVT-485_422-1) and a Full-Duplex monitor cable (CBL-Full-1A), the 232Analyzer software can capture not only the data flowing between the RS485 devices but also the data direction. Connect 485+ and 485- of the serial devices to A and B of the converter respectively. Switch to full-duplex monitoring mode in the 232Analyzer software. Learn more...

Yes, by using two units of RS232/RS422 converters (e.g. CVT-485_422-1), the software can capture not only the data flowing between the RS422 devices but also the data direction. Connect TX+ and TX- of the serial devices to RX+ and RX- of the converters for both sides of the connections. Switch to Full-Duplex monitoring mode in the 232Analyzer software. Learn more...

Yes, by using a Full-Duplex Monitor cable (CBL-Full-1A) and two units of RS232/TTL converters (e.g. TTL-232-1 or TTL33-232-1), the software can capture not only the data flowing between the TTL devices but also the data direction. Learn more…

Please refer to the table below for the recommended hardware accessories:
Direction Indication RS-232 RS-485 RS-422 TTL 5V TTL 3.3V
Yes 1x USB-232A-1
1x CBL-Full-1A 1x USB-232A-1
1x CBL-Full-1A
2x CVT-485-1
2x PWR-5_US-1
2x GCH-9_MM-1 1x USB-232A-1
2x CVT-485_422-1 1x USB-232A-1
1x CBL-Full-1A
2x TTL-232-1 1x USB-232A-1
1x CBL-Full-1A
2x TTL33-232-1
No 1x USB-232-1
1x CBL-Half-1 1x USB-232-1
1x CVT-485-1 - - -
More info on:
Serial port monitor (monitor RS232/RS485/RS422/TTL communications)
Serial port terminal (control RS232/RS485/RS422/TTL devices)

232Analyzer software is a Windows-based program, and the actual timestamp accuracy depends very much on your PC's hardware and software characteristics, such as operating system, overall PC performance and the serial hardware used. To achieve the best accuracy, we recommend the following:

1) Disable other programs or resource-consuming tasks, such as anti-virus software or other windows programs, if possible.

2) If you are using the USB-RS232 converters, you may reduce the ""latency timer"" to the minimum of 1ms. Please see our FAQs here.

What COM port hardware do you recommend for best timestamp accuracy in monitoring mode?

If you encounter the problem of "Error 380", please download and install 5.6.1 and/or later versions.