View Full Version : Polling Modem Solution

July 23rd, 2009, 10:51 AM
have a potential upgrade and would like to find a modem that will work better than the current system.

Basically, we will have an HMI. This HMI had WinPLC with an interface that used the internal modem to dial out to 8 sites in a polling fashion to get updates to Modbus data points.

The plant went to RSView recently and they would like to put this system on RSView. In the future, we will go radio modems, but for now we are stuck w/ phone lines.

I'm looking for a programmable modem that can be setup to dial various numbers in a polling fashion to achieve the same task. I do not want to have to write an interface in RSView to achieve this goal.

Any ideas....



July 23rd, 2009, 12:19 PM
Have you looked at the DF1 Polling Master driver in RS Linx?

July 23rd, 2009, 12:27 PM
I have never used this feature of RSLinx, but it looks like it may do the trick.

However, we are not talking DF1 but Modbus, have a work around for that?

July 23rd, 2009, 12:31 PM
Short answer no.

What kind of hardware is at the remote sites?

July 23rd, 2009, 12:52 PM
WAGO 750-316 Modbus Head attached to an existing modem via serial cable.

July 23rd, 2009, 01:37 PM
You can install a 5/05 processor. Configure the serial port as a Modbus master. Poll your remotes with the SLC. Use the Ethernet drivers in RS View to communicate with the SLC.
OR Change your remote site hardware to AB (Micrologix) and use the half duplex polling master in RS Linx.
OR write a communication program in VB to communicate with the remote sites (which you donít want to do).
There are many other ways to do this, these are just a few.

July 23rd, 2009, 01:47 PM
Yeah, those are all viable options but more than what we want.
I was hoping to find a "Black Box" that included a modem in it, that we could program to poll the 8 phone line numbers and pass through the serial communications established between the modem and the remote site directly to RSView (or the Modbus driver loaded on the PC)

AB always makes it difficult for anything other than their items!

July 23rd, 2009, 02:10 PM