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For Industrial Automation Products - sixnetio.com
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 Industrial Telephone Modems

Just click on a question below to get the answer:
Sales FAQ    (Go to Support FAQ)
Support FAQ

What are the advantages of a SIXNET industrial modem?

There are several. Go to Advantages to Industrial Modems for details.

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Can an industrial modem communicate with the modem in my PC?

Absolutely! SIXNET industrial modems use a ruggedized version of the modem chip set used in PC modems. The firmware and command set is identical. You can even connect an industrial modem as an external modem on your PC.

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Will these industrial modems communicate with my PLC?

SIXNET industrial modems have been successfully used with PLCs manufactured by Allen Bradley, Omron, GE Fanuc, Automation Direct, Group Schneider, Mitsubishi, Siemens and others. We have written technical notes on the PLCs we have helped to test. If you need assistance with another PLC, we are eager to help. Contact Us.

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How do I configure the modem for use with my PLC?

The Modem Setup Wizard, an easy to use Windows setup utility supplied with the modem, guides you through this process. Install and run the Wizard, click the "Open Configuration File" button, and select a *.6ms file name that matches your PLC model. Can't find a file to match your PLC? Chances are one of the existing configurations will work for your PLC. (Most PLCs have similar characteristics.) Or check for the latest .6ms files on-line. Use the Wizard to create your own custom configuration that can be stored on your hard drive: run the Modem Setup Wizard, select modem model, PLC communications parameters, self-dial parameters (VT-MODEM-2 only), modem parameters, RS422/485 parameters (VT-MODEM-3 only) and save to disk.

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Do I need to know AT commands to configure the modem?

Generally, no. Just use the supplied Modem Setup Wizard to quickly and easily configure your modem. Most major modem parameters can be set just by clicking a box. Click here for more details on the Modem Setup Wizard.

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Do I need a special cable to connect the modem to my PLC?

The modem ships with a straight-through 9-pin cable, which connects from a serial port on your PC to the modem. Use this cable to configure the modem. Check the modem on-line help or your PLC documentation to verify proper cabling when connecting modem to PLC.

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I need to replace an older 2400 or 9600 baud modem to talk to legacy software. Advice please?

When you configure your new industrial modem, there is an option presented in the Modem Setup Wizard, supplied by SIXNET, to use a fixed baud rate. You can also turn off the modern communications options such as error correction and data compression that may be incompatible with your legacy software. In fact, you can use the pre-configured file, "9600mdm.6ms" presented on the first page of the Wizard. Refer to Technical Note #606 for more details.

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How do I mount the modem in my cabinet?

All SIXNET industrial modems come with two mounting options: Snap directly onto a DIN rail or flat panel mounting.

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I'm an OEM. How can I warranty the systems I sell for an extended period of time?

When ordering an industrial modem, simply select the extended warranty option to receive the protection of limited manufacturers warranty coverage for a full 36 months.

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We export our systems. How can I be sure that the industrial modem will work in the countries we ship to?

SIXNET industrial modems have been tested to comply with both U.S. and International phone standards. There are thousands of SIXNET modems in use around the world. They were designed specifically for OEMs who wished to ship identical systems all over the world.

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I just got my VT-MODEM. What should I do first?

First, install the Modem Setup Wizard. Then, using the supplied VT-CABLE-MDM, connect your SIXNET modem to a serial port on your PC. Next, run the Modem Setup Wizard. Check for a pre-canned configuration file (.6ms) for your device. Then, just step through the windows and set your desired parameters. Finally, write the configuration down to your modem. Remember to save your configuration for future use. Now you can connect the modem to your device and try making a dial-up connection.

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Why do I get a communications error when I try to write my Modem Setup Wizard configuration?

Make sure you are using a VT-CABLE-MDM or exact equivalent. Refer to the VT-MODEM User Manual for the cable pin-outs. When you try to write your configuration watch the TD and RD LEDs on the modem. If you see neither flash then you have a wrong or bad cable, you have selected the wrong com port on your PC, or your PC's com port is locked up (cycle power on the PC). If only the RD LED flashes then try cycling power to the modem.

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I dial but why doesn't the VT-MODEM connected to my remote device answer?

Obviously, make sure you have configured the SIXNET modem to auto-answer. Also, make sure the modem is connected directly to an analog phone line. A digital or PBX line may not work properly.  Finally, check how you have configured DTR to operate. Try setting the modem to ignore DTR.

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I can dial and make a connection but why can't I talk to my device?

Make sure that when you configured the modem with the Modem Setup Wizard that you used the same baud rate and com settings that your device is currently configured for. The modem remembers these settings and that's what it will use to communicate to your device when a call comes in. Also, some devices use protocols that require special gap timing. In order for these protocol's to work properly over the modem you must disable all advanced features such as error correction and data compression. Also, you must set the modem to use a fixed baud rate that matches the baud rate of your device.

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When I exit HyperTerminal why does the VT-MODEM hang-up?

When HyperTerminal is exited it will drop the DTR signal on the com port. If your SIXNET modem is configured not to ignore DTR it may interpret this as a signal to hang up your connection. Simply use the Modem Setup Wizard to configure your modem to ignore DTR.

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What is the fastest speed the VT-MODEMs will connect?

The VT-MODEMs maximum connection speed of 33600 bps with ideal phone line conditions. The fact is telephone lines are rarely in ideal conditions, and with a modem-to-modem connection that means the maximum speed the modem is liable to connect is 19200 bps and probably more often at 9600 bps.

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Should I use phone line surge suppressors?

This can only help to supply a more reliable connection. Since telephone lines are dynamic and subject to the elements such as power spikes and lightning strikes having surge suppression on all incoming lines will highly reduce the chances of your equipment getting damaged. Check out SIXNET's phone line surge protector.

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Can the VT-MODEM operate in 11-bit Mode?

The SIXNET VT-MODEM-1,-2 and -3 work in 'True” 11 bit mode (1 start bit, 8 data bits, 1 parity bit, 1 stop bit). They use 11 bits all the way through the transmission, from computer through the modems, and over the telephone lines to the PLC. In contrast, the SIXNET VT-MODEM-4 and -5 strip out the parity bit during data transmission over phone lines from the dialing modem and put back the parity bit in the receiving modem. This will give you faster transmission speeds because there is less information to pass. However, you should note that the protocol in some 3rd-party devices might be sensitive to this.

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How much does using Data Compression increase data throughput?

The data compression can be as high as 4 to 1 in ideal conditions, so if the modem connects at 33.6 kbps the serial data available to the rs232 port could go as high as 134.4 kbps. If the available data rate is higher than the rs232 port can keep up with the receiving modem tells the sending modem to wait until the receiving modem can send the data out the rs232 port. Since phone lines are not ideal usually the data cannot be compressed that much, so the average speed is much lower than 4 times the modem rate.

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Can the VT-MODEM work on an ISDN or Digital telephone line?

SIXNET Modems cannot work over ISDN or digital phone lines directly. The VT-MODEM doesn't have the capability to support the digital ISDN signals, and uses only analog phone lines to transmit data.

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How reliable is the on-hook relay of the VT-MODEM?

The VT-MODEMs uses a solid-state relay within the modem chipset. When you look inside our modem you will be able to see a distinctive set of microchips. These chips are the ‘brains’ of the modem. Inside one of those chips is the solid-state relay that switches the modems into the on or off hook state.

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