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1734-IE8C Major Channel Fault
1734-IE8C input module went bad. Replaced module still all channels solid red.

Need help troubleshooting 1734-IE8C input module. All channels show solid red so I replaced the module and had the same results. Any and all help would be appreciated.

Moderator's Note: 1734-IE8C is manufactured by Allen-Bradley

By Bob Peterson on 16 June, 2017 - 3:31 pm

Blinking red on the channel indicator usually means out of range. no idea what solid red means and the AB literature is not especially helpful other than suggesting it is a more serious error.

Knowledge base article 493193 suggests:

A solid red LED condition on these modules is caused by having no field power applied to the POINT I/O bus.

When using a 1769-L16 or 1768-L18 controller with these POINT I/O modules, make sure that FP+ and FP- pins on the controller have 24VDC applied to them.

If using the modules with a 1734-PDN adapter verify the V and C terminals of the adapter are receiving 24VDC as well.


Check the field power supply to the PLC FP+/FP- pins (if they're part of a CompactLogix chassis) or PDN adapter V/C pins:

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Installation manual: