Hi everybody,
I have KOYO KOSTAC SR-20EX. It's not working now.
When switching ON power, only LED POWER on the CPU module is lit. Other LED ( RUN, BAT, CPU) are unlit. DC output on the power supply module is only 23,62 V. Battery's voltage is 2,94V.
Could you please tell me the problem of my PLC?

What I need for programming this type of PLC ( which cable or adapter and which software?)

Thank you in advance.

Offhand, I'd say either it has lost the program or is just toast. Either way it you might be out of luck.

That looks to be pretty old. It isn't shown on the Koyo current parts list. It was made from December of 1992 to April of 1995. It was programmed by a software package called Kostac CAD and it isn't supported by Directsoft so getting support from AutomationDirect isn't likely.

It looks like unless someone has a copy of Kostac CAD handy, you may have to replace it with a different PLC.

Did you able to switch the PLC to run mode? Do u have any handheld?