Hello everyone,
we supplied a system to a client with a panel contains s7-1200 CPU along with digital and analog I/O cards, it was commissioned and working fine.
they called us for a problem they had when i went there thinking it's just a bug in the code but we found the following:
1- the PLC is OFF power even i measured 23.8 vDC n it's terminals but for a period of time it powers ON
for 2 minutes then OFF again. also when i removed the 24 supply wire for some time and then connect it again, the PLC powers ON then after 2-3 minutes, again OFF.
i supplied the PLC directly to the power supply and the same result.
2- they added s7-200 PLC to the panel by their own and i noticed that they made a "jumper" from our
I/O cards to their own s7-200 cards which they installed as a back-up so that signals will be distributed on both cards ( i think it's wrong but i need confirmation from experts - s7-200 uses 220 AC )
so what could be the cause ?
we supplied a system to a client with a panel contains s7-1200 CPU along with digital and analog I/O cards, it was commissioned and working fine.
they called us for a problem they had when i went there thinking it's just a bug in the code but we found the following:
1- the PLC is OFF power even i measured 23.8 vDC n it's terminals but for a period of time it powers ON
for 2 minutes then OFF again. also when i removed the 24 supply wire for some time and then connect it again, the PLC powers ON then after 2-3 minutes, again OFF.
i supplied the PLC directly to the power supply and the same result.
2- they added s7-200 PLC to the panel by their own and i noticed that they made a "jumper" from our
I/O cards to their own s7-200 cards which they installed as a back-up so that signals will be distributed on both cards ( i think it's wrong but i need confirmation from experts - s7-200 uses 220 AC )
so what could be the cause ?