Debounce reed switch contacts in FPGA

[hasun]

To my compactRIO with FPGA I have a C-series Digital IO (9401) with a RED relay on four different inputs. The relays creating contact bounces within 200µs at closing. I would like to debounce the input signals, Which are digital, for period time measurements.

Since I am new to the system it is not obvious to me how to solve this in the FPGA. There are a few ideas on this forum for similar problems for use in the host computer. However, they are to slow and not possible implement in the FPGA.

I would appreciate some ideas on this task.

[Coq_Rouge]

Perhaps a small debounce capacitor may solve your problem. Google debounce capacitor. It is just a tip

[johnsold · Accepted solution]

Typically digital debouncing involves a small state machine which requires that the input stay in the new state for n clock cycles. It resets if the input reverts before the timeout.  This should be fairly easy to implement in an FPGA, although I have not worked with them. For your case n would be selected to result in a time larger than 200 us.

Lynn