For lower than 2kHz frequencies smaller or bigger duty cycle might be available, considering previously mention conditions.
+
+
Also, devices that’s support 2kHz on DIN1 (see Table 1) have same limitations as DIN2, but also minimum voltage provided to DIN1 by pulse should be 7.5V or grater. Lower than 7.5V pulses add pulse rise time. For example, at 3.6V pulse rise time is ~500us comparing to 7.5V at 60us (FMB920). Pulse counting might work at these low voltages with low frequency but it is not reliable.
==Advanced pulse counter parameter in configurator==
==Advanced pulse counter parameter in configurator==