Radio Taking down PLC and clearing memory

[kroxic]

Anyone ever have a problem with a handheld radio taking down a PLC? I didnt know it would be that much of a problem until a coworker was testing a program and he clicked on the radio to say "ok I am going to close the value" and all the lights flashed and the plc reset itself. This was on a GE VersaMax by the way.

I had no idea these things were that susceptable. Are there standards that everyone id going by to avoid such behavior?

 

[Tharon]

I had no idea these things were that susceptable. Are there standards that everyone id going by to avoid such behavior?

They shouldn't be. It may have just been coincidental. Try it out a couple more times to see if it is repeatable.

There are standards. Underwriters' Laboratories (UL) and CE set standards and their logos are on most electronics.

 

[OZEE]

I was in a plant once where the operators would play with RC cars when they were bored. Occasionally, the PLC (TI585) would get stupid and all locked up. I don't remember that it ever dumped the program, but it would lock it up.

 

[bobwithdana]

I worked at a place where keying up a motorola radio would reset the panelview plus 1000 terminals. we had 31 terminals and it would do it to more than one if you got to close.

 

[curlyandshemp]

Anyone ever have a problem with a handheld radio taking down a PLC? I didnt know it would be that much of a problem until a coworker was testing a program and he clicked on the radio to say "ok I am going to close the value" and all the lights flashed and the plc reset itself. This was on a GE VersaMax by the way.

I had no idea these things were that susceptable. Are there standards that everyone id going by to avoid such behavior?

On recall on the older SLCs 5/03 & 5/04 there used to be a choke supplied that was to be clamped onto any cable connected to the DF1 port to eliminate RF. I also recall on occassions these SLCs would loose its program and that usually occured on CPUs that had something connected to the DF1 port.

 

[Mickey]

Many years ago at plant I work at, a fellow worker had a heart pacemaker.
You did not want to key your hand held radio around him.

 

[Greg Dake]

Most certainly

We have older chart recorders in our plant where the pens will go full scale when you key your radio next to one. We covered their doors with copper mesh and it took care of the issue.

Also, the paper shredder in our office will start if you key your radio next to it. We just use the standard Kenwood 2-way radios...

Greg

 

[DwalterE]

If your coworker was connected to the PLC with a laptop programming terminal, it's possible the radio got into the PLC via the laptop.

I had an 800 mHz radio knock a laptop flat onto its back - right now! It was connected to a PLC 5/04 at the time, but the PLC kept right on chugging.

 

[kroxic]

He told me just a bit ago that he got ahold of GE about it and they said that if you have a 5W radio within 3 feet of the plc it will kill it. Or was it 3W within 5 feet. I dont remember really but it just surprised me that this is normal behavior and they just told him outright what it was without beating around the bush. Guess we will have to start putting signs on the doors to tell workers to keep radios off when entering the control room.

 

[scottmurphy]

I've been commissioning a plant, and if I held the radio to close to the laptop, the laptop would re-start itself!! There was the odd occasion, where I hadn't saved what i was doing either

 

[dmroeder]

At the plant I worked at, we had a computer that we would allow this integrator to use. He was a real arrogant jerk. Every time he would use his Motorola radio next to the PC, the CD-ROM would open.

Oh wait, that was me effing with him from another computer... my bad...

 

[Protiusmime]

Likewise et al.: If our PLC cabinet doors are open and we key a HT within 2-3 feet, spurious emissions (to the plc at least) cause problems in the PLC power supplies. We always make sure to close doors before transmitting.

 

[Jim Dungar]

There are standards. Underwriters' Laboratories (UL) and CE set standards and their logos are on most electronics.

UL does not have any standards for RFI/EMI interference from/to other devices. In the US these are FCC issues.

CE, on the hand, is very concern about RFI/EMI and has strict standards.

 

[Tharon]

UL does not have any standards for RFI/EMI interference from/to other devices. In the US these are FCC issues.

CE, on the hand, is very concern about RFI/EMI and has strict standards.

Oh, sorry. I just remember seeing stuff about "meets all requirements for interference" and all that jargon.