I dont really understand what happened to my plc. we have 2 central panel at our production floor which is equipped with plc. there was a power outage and after the power was restored the 2 central panel refused to start up. The panel did start but the 2 plcs do not accept any command from the interactive display unit. please, how do I rectified it. am so surprise that 2 plcs from different panel can break down at the same time. pls reply.

 

There any number of reasons for what you are describing. Unfortunately, you have given us almost no information to work with.

Did the PLCs go out of run mode?

What brand/model of PLCs? What about the displays?

is the communications network still up? Could be they are all running thru the same ethernet switch and maybe it is what failed.

what do your various diagnostic indicators (leds or displays) on the PLCs show?

There is just no way to diagnose what may or may not have happened w/o a lot more information.

--
Bob
http://ilbob.blogspot.com/

 

Fabunmi,

it is difficult to suggests something useful to rectified you problem if your information is not detail enough. Please provide use detail information as below:

- Your PLC brand, family, type, programming language, etc

- Your display unit brand, family, type, programming language, etc

- Communication and connection details between your PLC and displays signal :RS232/422/485, ethernet.

what protocol to use: modbus, Ethernet/IP, Profibus,

what media : Fiber optic, UTP, coaxial, address of each device,

which is master or slave, distance between PLC and display, etc

Ikhtiander

 

Thanks my friend, the plc later come up. what I discovered was that the safety network control inside the panel doesn't supply 24v dc to the plc unit of the slave panel. thanks.

Regard,
Femi.