External Moderators tmoulder Posted January 7, 2021 External Moderators Report Share Posted January 7, 2021 Hello All, I have a robotic welding application, using a Unitronics V570 with ethernet communications to a motion controller, 2 robots and a camera system, all Modbus TCP. About a year ago, we switched the plasma welder on the line to TIG welders. This was an enormous cost savings over the old ones, which were obsolete anyhow. Buuuuttt... (You knew there was a "but" coming somewhere, didn't you?) Since the conversion we have had an intermittent-but-persistent problem where when one of the welders strikes, it knocks out the ethernet communications. The TIG torch uses a burst of RF to establish the arc, and this is the moment the drop takes place, if it happens at all, which it can go weeks without happening, and then it comes raging back. I've taken a plethora of steps to try and correct this issue: The machine is more heavily grounded than my smart-alec teenage daughters. I've checked the paths to ground for everything on the system, and I cannot find anything I've missed in terms of grounding. Shielded Cat5e cables throughout, then took the additional step of replacing those with fiber optics. The longest single conventional cable is now 2 meters in length, and isolated from the rest of the system. Replaced the V570 and the ethernet card. In terms of troubleshooting, I added some counters to the PLC program, and it appears the the link is being lost. It reconnects automatically, but by then, it's burned a hole in the part. For mitigation, I switched some of the responsiblity for the welding movement from the PLC to the motion controller, so even if communication is lost for 1 second, the welding process continues unabated, and comms are restored before the weld move finishes. The nature of the drop (link lost) makes me think the issue is somewhere with the PLC itself. The fiber optic convertor for it is located in the same operator panel, connected by a 1 meter shielded cable, all contained within a fully grounded enclosure. I'm thinking a different ethernet card may be in order. I've pack-ratted several of these over the years, but can someone explain to me the difference between the V200-19-ET1, the V200-19-ET2, and the V200-ET-E? And is there some version that offers more robust performance for electrically noisy environments? Thanks! TM Quote Link to comment Share on other sites More sharing options...
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