connection to a PLC via GSM modem

Generally, connections to GSM modems are accomplished across the internet (for public connections), or private networks if you have a dedicated connection into the carrier. Is the config port you are accessing on the Horner PLC serial? If so, and if you are required to use a serial connection on the PC end, you can do a modem to modem connection with the GSM modems on each end. We’ve actually done this with a serial polling system. You make the PC end a client, and the PLC end a server, pointing the client to the server. The exact settings are modem dependant, but I have used a few types and they all have the same general functionality,

We have several GSM and CDMA type modems in the field and they work well enough, particularly for non-critical applications such as remote programming access. What carrier are you using? What type of GSM modem?

If you are using an ethernet port on the PLC, one issue usually overlooked is that the wired side of a celluar (GSM) modem is a local area network. The setup of the ethernet port on the PLC must match the LAN setup on the modem. Also if you wish the acces the PLC remotely, then you must setup some kind of routing in the modem to direct outside connections to the PLC port address. Exactly how this is done is modem dependent.

This is not a trivial setup, especially if you also need to make the setup secure. I know been there and done that.

Mark,
I've used these guys, great support. I had no idea what I was dooing when I started, they walked me through the entire process, worked great when we were done.


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