FM 350-2 doesn't count pulses from laser sensor.

Hi,

I seem to be having a problem with the FM350-2 Counter module.

I have connected a ROLS-P sensor from Monarch Instrument to the FM350-2.
ConnectionsI have made are:

common ->M (pin 22)
V+->DC 8,2V (pin 39)
signal -> A0 (pin 3)

the sensor itself has a green LED that flashes when a pulse is generated.

When the sensor is generating pulses the counter doesn't seem to see them, nothing changes.
When I connect a signal from a pulse generator the Counter does give me a measurement.

The settings are set to accept a NAMUR signal and do a frequency count.

I have connected a scope to check the sensor signal, does it matter if the length of the pulses is not equal to the length between them?

If anyone has an idea why the counter isn't counting, please throw me a bone ;)

Thanks in advance,
G. Mortier