Problem with SLC500 analog I/O module NIO4V (beginner)

[Chireadan]

Hi,


Sorry for my bad english, I'm from Poland.


I've decided to learn basic PLC programming as hobby and to maybe get a better job. I have absolutely no education in this field, I'm a metallurgical engineer. I planned to learn on two PLC "systems" - Siemens S7, and Allen-Bradley (most common here). I've made a breadboard-style "PLC simulator" consisting of Siemens S7-1200 CPU with ET200SP with 4 I/O modules, buttons, LEDs, relays, thermocouples, and so on. I also wanted to learn on AB PLC, but I've already ruined my budget, and AB hardware is notoriously expensive. I've managed to get for free, from electronic "scrap heap" only an ancient SLC500 system, consisting of:
10-slot chassis
1746-P2 power supply
SLC50/2 CPU
2x 1746-IA logical input modules
2x 1746-IB logical input modules
3x 1746-OA logical output module
1746-NT4 thermocouple module
1746-NIO4V analog I/O module.
- 4 spare IA and OA modules, not installed.


The controller works, but I can't manage to use the NIO4V I/O module, i think it may be broken. The module is detected, and removing it or changing slot will cause controller to fault. However the "POWER" led on module is not lighting. Both analog outputs produce voltage which is swinging from -600mV to +2,5V, regardless of the integer written to output. I suspect the module internal +/- 15V power supply is damaged. This should be possible to repair, but I have no idea how to power the module with +24V while it's pulled out from the chassis. Or maybe it has to be initialized in some special way?

 

[Mickey]

The module is detected, and removing it or changing slot will cause controller to fault.

Did you do this with the power still on to the PLC?

If so , very bad.

They are not cheap.

https://www.google.com/search?q=174...BBpIBBTAuNC4xmAEAoAEByAEKwAEB&sclient=gws-wiz

 

[Chireadan]

No, I've only exchanged the modules with power turned off. I assume the module cannot be completely dead, because controller will fault when powering it up with this module not present or installed in another slot. However, from the module manual I understand, that the communication part of module is separately powered from 5V bus, and the A/D and D/A converters from the +24 bus via the internal DC/DC converter on the module.