Logic for cellular modem Communications


#1

Hello, Anyone have a proven set of charts or subtroutines to enable and manage cellular modem communications with an LCM4 controller to a remote serial B-3000?

I’m trying to assist a neighboring small utility with a SCADA system for water tank level control over cellular.

Verizon seems to be the better provider in the area.

I manage 40 plus OPTO controllers thousands of I/O and all on Fiber or Ethernet radio at our utility and yet I have no references as to proven logic over a cellular modem.

Any help would be appreciated.

Thanks in advance,

rculp


#2

Hi rculp,

Welcome to the forums!

Great question, I have two trains of thought…

  1. Dont worry about it. Let the modem handle it.
    Sounds odd, but we have quite a few customers doing just this…
    They are using Ethernet cell modems and so its a simple plug and play solution.
    They put one at the controller end and then another at each ENET brain and it acts just like a long bit of wire. (Note, doing it like this will require you to think about your poll rate vs data costs).
    Other than setting up the modem, there is nothing more to configure… It really is just plug and play.
    We have a few customers using these Ravens;
    http://www.sierrawireless.com/productsandservices/AirLink/Configurable_Intelligent_Gateways/AirLink_Raven_XE.aspx

  2. Check out this summer code contest entry from Carl;
    http://www.opto22.com/community/showthread.php?t=315
    You might be able to bend it, or just straight out use it to suit your application.

Lastly, its not an answer, but it sounds like you are pretty comfortable in the world of Opto and so have you considered using the event reaction abilities of our brains?
This may give you enough basic control at each water tank that you can wind back your poll rate considerably.

Anyone else got any control going on over cell modems?