remote contol of SLC 500 fixed I/O

[RS Problems 0]

Does anyone know of a way to connect a modem to a SLC 500 fixed I/O with nothing but a DH485 port? I would like to be able to have the PLC call my phone under certain cercumstances and possibly be able to call the PLC and activate inputs.

[Ken Roach 194]

You would probably need a discrete-triggered autodialler modem if you wanted the controller to initiate a call to your modem. Calling in to the controller is easier, since you control the dialler. DH485 protocol won't run over modems; you need a DF1 to DH485 converter. The one I use the most is the slot-mounted 1747-KE module. If you don't have expansion slots on your Fixed SLC, you will need an external module like the 1770-KF3 (discontinued, I think) or the DataLink DL3500.

[RS Problems 0]

Great answer! Thanks.

[RS Problems 0]

I found a cheaper way to do it, for anyone who is interested. $6 to be exact. Pick up a $6 phone, plug it in, and dial the number you want to call. Disconnect the phone and solder wires to the GROUND, HANG-UP, and REDIAL buttons. All you need now is two outputs and a few lines of logic. Edited 7 Dec 2007 by RS Problems