woodward_uk
Lifetime Supporting Member
Hi There
I have a remote rack containing 2 off 1746-NI16I analogue cards. Comms is via SN \ ASB and I have attached the section of ladder program showing how the block transfers are handled.
When the PLC is switched to Run Mode the configuration words are written to each block of channels, the channels all respond ok and the Config Complete Latch is set ok. However a few seconds after this has occured, one or two channels will sometimes stop responding and will not read any analogue data. The channel processed bit also goes off for these channels. This happens roughly 50% of the time that power is cycled to the plc.
There is no pattern to which channels fail, and it can happen on either card in the same random way. Cycling the power once or twice will usually bring the missing channels back.
If anyone could help I would be most grateful.
Steve
I have a remote rack containing 2 off 1746-NI16I analogue cards. Comms is via SN \ ASB and I have attached the section of ladder program showing how the block transfers are handled.
When the PLC is switched to Run Mode the configuration words are written to each block of channels, the channels all respond ok and the Config Complete Latch is set ok. However a few seconds after this has occured, one or two channels will sometimes stop responding and will not read any analogue data. The channel processed bit also goes off for these channels. This happens roughly 50% of the time that power is cycled to the plc.
There is no pattern to which channels fail, and it can happen on either card in the same random way. Cycling the power once or twice will usually bring the missing channels back.
If anyone could help I would be most grateful.
Steve
