Just wondered also, whether you could use an analog input board in conjunction with ADC conversion.
Yes, according to related manual, analog inputs requires additional FH board, I don't have it. Moreover, the AD conversion speed is 1 ms (typical), so IMO I would not consider this option.
Some options to ponder & investigate:
Use ethernet I/O modules like WAGO, Beckhoff, others...do they have any high speed input modules?
What is your reaction time requirement? If not too great, then you could intercept the signals with a cheapo PLC with high-speed input module, latch & send > the signal so Kawa could catch it & process it with a separate task
Signal period is 12,2 ms (12 ms LOW + 0,2 ms HIGH), so every sub-task should be completed within 12 ms.
This could be a valid option, even if the ethernet port is used to send position to pc station. Anyway, if you can suggest me any WAGO/Beckoff/others product with high speed input it could be useful for further investigation.
I called KAWaSAKI Distributor Service, they told me that there isn't any additional board with fast input (it sounds strange to me).
By the way, they also suggested to try using the HSENSE instruction that enable interrupt on Input and catch rising/falling edges within 2 ms. Next days I will try this option too.