RSLogix500 - counters with AB 1762-IQ8

Howdy folks!

I'm putting a higher speed counter in place (AB 1762-IQ8), and am unsure as to whether I need to use the HSC instruction in the ladder, or whether a CTU/CTD would do the job for something that would see around 70 counts per second max. Any takers?

plaurent said:

Howdy folks!

I'm putting a higher speed counter in place (AB 1762-IQ8), and am unsure as to whether I need to use the HSC instruction in the ladder, or whether a CTU/CTD would do the job for something that would see around 70 counts per second max. Any takers?

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I personally would use the onboard inputs of the PLC. Depending on the model, the first four inputs of the PLC are setup for high sped input. The fist 8 inputs of a ML1500 are for High Speed inputs.

You can use the HSC instruction or the CTU/CTD whchever you prefer. Only the ML1500 has two HSC instructions. I would also use a ONS instruction before the CTU instruction.

Hope this helps