OptoNews Tech tip: Can multiple devices talk to a PAC controller?

Posted by Jean Femia on Oct 7, 2015 2:46:37 PM

SNAP PAC S-series controllersA SNAP PAC controller communicates over Ethernet. Is it OK if two PCs are trying to communicate with the PAC at the same time, or will they interfere with each other? 

This was the question in a recent OptoForum post, and it got a quick answer: yes, it's OK.

Whether it's a standalone S-series or a rack-mounted R-series PAC, you can have many devices simultaneously requesting data from and sending data to a SNAP PAC.

In fact it's pretty typical to have more than one. For example:

  • PAC Control on a PC
  • PAC Display, or a third-party HMI like Wonderware
  • a groov Box or Server updating data for a mobile operator interface
  • Modbus/TCP equipment
  • a company database 
  • even an Allen-Bradley PLC 

The reason the SNAP PAC can be so communicative is that it uses Ethernet and TCP/IP (and several other protocols). These standards allow multiple conversations over the same wire at the same time. 

As more than one poster in the Forum noted, though, you'll need to be careful if more than one device can change variables and I/O. Read the Forum post for more.

And congratulations to Joey@JAKing, the poster of this question. He's the 22nd person to have posted more than 22 times on the Opto 22 Forum!

The OptoForum is a great place to get the answers you need, 24 hours a day, 7 days a week. The forum has seen nearly 4000 posts since its inception in January 2012, and more than half of forum members have posted at least 3 times. Post your question today, or add your expertise to help someone else.

Read the OptoForum post

Topics: Tips, optonews, PACs, Integrators, Networking, OptoNews 2015-10-07

Written by Jean Femia

Jean Femia writes about technical subjects and has focused on automation and control systems for more than 15 years. She likes learning about technology and taking corners in her Honda S2000.
Find me on:

    Subscribe to Email Updates

    Recent Posts

    Posts by Topic

    see all