Hi,
I am looking into some issues on a 1734-IB8S and was just trying to get my head around the safety test pulses that are configured.
I understand that they are/can be used to detect wiring faults with associated inputs. My system has 3 inputs connected via test pulses, 1 goes through a safety area relay N/C contact and back to an input, x2 go through an adjacent PLC's safety area relay N/O contacts and back to other inputs.
As I keep getting intermittent combined input status faults on the card I removed the inputs, however I am unsure as to why I don't get an instant fault when removing the inputs as I would have thought the input would be expecting to see the test pulse signal and is instead getting nothing?? They look as though they are configured correctly, with correct Test Pulse configured to the right input.
Any help clearing this up would be appreciated.
Thanks
I am looking into some issues on a 1734-IB8S and was just trying to get my head around the safety test pulses that are configured.
I understand that they are/can be used to detect wiring faults with associated inputs. My system has 3 inputs connected via test pulses, 1 goes through a safety area relay N/C contact and back to an input, x2 go through an adjacent PLC's safety area relay N/O contacts and back to other inputs.
As I keep getting intermittent combined input status faults on the card I removed the inputs, however I am unsure as to why I don't get an instant fault when removing the inputs as I would have thought the input would be expecting to see the test pulse signal and is instead getting nothing?? They look as though they are configured correctly, with correct Test Pulse configured to the right input.
Any help clearing this up would be appreciated.
Thanks
