Archive for category Ethernet
People will fire up a new UDC 1/4 DIN loop controller, like a UDC2500 or UDC3200, and discover that the lower display periodically flashes an error code: UNPLUG. But what does it mean? Is something wrong?
A search of the pdf version of the manual hints that the Modbus Ethernet communications is involved:
The Ethernet status screen shows the network status of the Ethernet Link. This may be accessed either via Ethernet or via Infrared Communications. For example, if the Ethernet cable is unplugged, then the instrument cannot send up the EUNPLGED diagnostic message via Ethernet.
But the word UNPLUG is nowhere else in the manual.
We’ve gotten feedback from several people who have asked what I carry around to deal with serial or Ethernet communications issues. So I dumped out my comm tool bag and here’s the list of all the stuff.
A customer has several UDC 3200 loop controllers with newly added Ethernet cards. He needed to configure each of the controllers’ IP addresses using Honeywell Process Instrument Explorer (PIE) software. Because the controllers are working in a 24×7 continuous process, he was concerned about how making those changes would affect each controller’s performance.
So he asked me: Would a PIE action of uploading config files from or downloading them back to a controller affect the controller’s performance?
In the past, I’d only ever changed a controller’s IP address when it was on my workbench, not when it was actively controlling a process. So I’d never paid attention to whether PIE communications would affect the controller’s output or its PID action. Since I couldn’t answer the question, I told the customer I’d run a test to find out for sure.