I'm looking for opinions from fellow readers on what modbus modems are used to interface with DCS.

Currently all my Mark V (2GT and 1ST) are connected to DCS via serial modbus from HMI. Modbus modems are connected at each end (HMI and DCS) for the connection- From HMI to modem via DB9 port; from HMI modem to DCS modem via RS485; from DCS modem to DCS module via DB9 port.

Currently the modem which I'm using (Develcon DS511A) which has been working well but now been obsolete. I'm looking for any similar modems which can be used to replace them. Any advice on what modems are used by other readers are greatly appreciated.

The existing modem picture can be found here:
https://picasaweb.google.com/115359...&authkey=Gv1sRgCImKsLaPntzQFg&feat=directlink

 

sd,

Is this a wired or wireless modem? We have a ZegBee wireless modem that supports Modbus RTU. Please see http://www.icpdas-usa.com/products.php?PID=3927.

 

The way it is described, it sounds like an RS-232-to-RS-485 converter, where the RS-232 port has a DB-9 connector.

One normally thinks of a telephone link when the word modem is used because the analog phone side uses modulated tones.

If the device is in reality an RS232-485 converter, then Google it. There are hundreds of RS-232/485 converters on the market, but for best service get those that have "isolation" and are NOT port powered. Get one the has a separate or integral power supply, but not one that derives its power from the RS-232 port.

 

The modem is a wired modem. Yes there are hundreds of RS232/485 modems available in the market but I would like to have the replacement which has been tested to be of no problem with Mark V as troubleshooting one of this is really handfull