Wrong COMM cable damaging PLC?

[unsaint33]

I was trying to connect a HMI (EZTouch Panel) to SLC500. The HMI had a PLC port (RS232/RS/422/485) 15 pin D-female connector. The PLC had a RJ45 RS485 port. I found an unlabeled cable with RJ45 on one end, and 9 pin D-male on the other end. I also found an adaptor that has 9 pin female and 15 pin male. So, I used the cable/adaptor to connect the HMI and PLC. Soon I started seeing smoke coming out of the PLC.

I shut off power to the PLC right away and removed the comm cable. When smoke settled, I restore power to the PLC and saw no more smoke. RXLinx cannot connect to the PLC anymore. I am sure the PLC is no good anymore.

I cannot believe using a potentially bad or wrong comm cable could fry a PLC. Can it?

 

[Dravik]

Sure, some of those ports have power lines. Shorting those or whatnot can kill the comm port but good.

 

[Bit_Bucket_07]

I cannot believe using a potentially bad or wrong comm cable could fry a PLC. Can it?

Absolutely. You saw it with your own eyes and you still don't believe it?

 

[unsaint33]

Also, the CPU FLT LED is flashing.

 

[Ken Roach]

The SLC-5/01, /02, and /03 controllers with a DH485 port have +24V DC on two of the pins, to power things like the 1747-AIC isolator or the Handheld Programmer. Connecting those ports with a random unlabeled cable can lead to damage to the controller or devices connected to the controller.

Since the FLT LED is flashing, the controller memory is probably cleared.

But if you can't connect to the controller with DH485 anymore, the port is probably damaged and you will need to replace the CPU.

 

[James Mcquade]

I would try another pc to communicate with the unit.
if one is not available, try to connect to another plc with the pc to make sure that port still works (insurance).
if you need to repair the plc, I use teamsesco for repairs, there may be others. they are very reasonable and stand behind their work. Note, they are a vendor and I am not associated with them.
james

 

[unsaint33]

I did try another plc with the same pc. Tried another AIC also. The plc is a toast. Luckily, i was testing the hmi so the PLC was from our storage. We have another one. Found used one on eBay for $40 if we need one down the road. Thanks