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Originally Posted by thingstodo
The analog input card does not appear to work.
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Happily, I had a poor connection on one jumper for the 1771-IF analog input card. The jumper was designed to be an input from an old linear power supply that indicates that the voltage from the power supply, +15V, common, -15V and a separate +5V and common are all stable and within published specifications.
The jumper was not making contact - either corrosion or errant insulation that was not properly stripped. It is working now thanks to two helpful experts at the PLCS.net forum.
Now, with proper voltage applied, the analog input card measures all 8 channels of 4 - 20 mA input signals
- 2, 4, 8, 15, 20 and 22 mA were applied to each channel, I DID observe under-range, 0%, 25%, 75%, 100% and over-range.
- the spare analog card also works fine.
Quote:
Originally Posted by thingstodo
Encoder
No progress so far on the encoder card. It does not accept communication signals from the PLC thus far.
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The 1771-IK encoder card does not work as I expected. Instead of having the 16 bits of input and output addressed as the first slot occupied by the 2-slot card ... the first 8 bits are accessed in the first slot and the second or upper 8 bits of the inputs and outputs are accessed as the first 8 bits in the second slot.
Many thanks to another expert at PLCS.net for pointing out the solution in Allen Bradley's knowledgebase tech support database.