High speed counter

Hi,

Iam having confusion in understanding high speed counters in simatic s71200 PLC. Is it a hardware counter. If i configured HSC as A/B counter whether the counting take place using hardware or using software?. What is the maximum frequency of pulses which can be fed into A/B inputs? I have seen in the configuration screen that this pin support upto 100Khz frequency input.

But what happens if i configure this as A/B counter. One input is connected to A and another input connected to B. How it affects the counting frequency.

Also which PLC offers high speed counter with maximum frequency?. Did siemens has any plc which supports high speed counter with more than 100 Khz?

Hi!

   Since HSCs can count much faster (up to 200kHz for S7-1200) than the PLC scan time, I assume that they are HW counters.

The link below might help to clarify things:

how-many-high-speed-counters-(hscs)-are-provided-by-the-simatic-s7-1200-plc