Modems overcome industrial interference

A Westermo Data Communications product story

Edited by the Engineeringtalk editorial team Sep 1, 2006

High quality telephone modems provide connection to remote devices and networks reliably within industrial environments and in areas of high level interference.

Westermo Data Communications has released a series of high quality telephone modems designed to provide connection to remote devices and networks reliably within industrial environments and in areas of high level interference.

The TDW-33, TD-36 and TD-36/485 are all ideal for industrial applications as they mount easily on to a 35mm DIN rail, have screw terminal connections, are tri-galvanically isolated and have an extended working temperature range of -25 to +70C.

The modems are also equipped with transient protection on the line side and a watchdog that monitors and automatically resets the modem in the event of a fault.

These functions together with remote configuration make them perfect for installation at unmanned sites and prevent the need of costly service trips.

They also have password protection, dial-back security and caller ID answering to ensure that only authorised users can communicate with the modem and any connected equipment.

The TDW-33 is a V.90 modem, meaning that it can support bidirectional datarates of up to 33.6Kbit/s on public switched telephone network (PTSN) lines.

The modem is available in a compact enclosure and has an RS232 interface supporting terminal datarates up to 115Kbit/s.

It runs from 12-36V DC power supplies.

The TD-36 has all the features of the TDW-33, but can also support bidirectional datarates of up to 33.6Kbit/s on leased lines.

A fast connect function ensures that leased lines can re-establish connections in less than 5 seconds.

The TD-36/485 extends the functionality of the TD-36 further with an additional RS422/485 interface supporting terminal datarates up to 115kbit/s.

The TD-36/485 also has a single digital input and output relay.

The input and output can be used to trigger, or be triggered by a number of different user defined events.

Both the digital input and output are galvanically isolated from the rest of the modem.

For ease of setup the modems are supported by the Westermo TD-tool configuration software.

The TD-36 and TD-36/485 also have DIP switches to assist configuration.

This latest range of Westermo modems make use of RoHS components and easily sourced digital signal processing equipment rather than conventional modem chipsets that are discontinued on a regular basis.

This, Westermo hope will ensure the products are available for many, many years satisfying the industrial markets need for long term availability.

"We feel that being able to provide identical replacement products that customers are comfortable with for a long time into the future is a strong selling point".

"Using fundamental design techniques for the TD modems we hope to prevent regular redesigns that have been regularly forced on us due to chips becoming unavailable", said Alan Bollard, Managing Director Westermo UK.