© 2022 Staheli West
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Tests
• Go to Menu > Diagnostics > Inputs Outputs > Analog Inputs and inspect channels
1-8 on cards 1 & 2 for normal readings. A faulty input card will often max out the
readings on one or more channels.
• If all channels on one card are maxed out, this indicates a faulty sensor or faulty wiring. Locate the
faulty sensor/wiring before replacing/swapping PLC input cards.
• If one channel is reading higher than normal, then the card can be swapped with the other input
card to see if the problem follows that particular input card. (WARNING: ensure you have replaced
the suspected faulty sensor. A faulty sensor can fry a new input card)
1. Use caution when swapping input cards. Always support the input card housing while removing
green wiring blocks.
2. While supporting the input card housing, remove the green wiring block.
3. Lift up the top and bottom tabs on the input card and gently remove from slot.
4. Make sure the multimeter is set to measure Ω (Ohms).
5. Connect one lead of the multimeter to the “0V” terminal and the other lead to channels 1-8 (one at
a time) as shown below.
6. A functioning channel reads about 100 Ω.
7. A non functioning channel will read some other amount (see below 33.68 Ω).
8. A functioning COM port will read about 0 Ω.
Test 13: Input Card Testing (See Fault 302)
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