We’re testing the NCD Relay Controller 4-Channel General Purpose SPDT + 8 Channel ADC ProXR Lite.
We’re running a parking application where we are getting inputs from the induction loops and then taking different action based on the condition of Loop-1, Loop-2, etc. Based on the inputs, we trigger UHF RFID reads for 750-msec and then take action depending on whether the tag is authorized…
We have code that is polling the state of the inputs 20-times/per second (50-msec) via:
170 2 254 166 80
It consistently returns 8-bytes of data as expected
170 9 255 255 255 255 255 255 255 255 170
Upon observing an input, we issue a command to operate a relay such as:
170 3 254 108 1 24
And may wait 1-sec and turning off the relay via:
170 3 254 100 1 16
In every case the relay commands are sent, we receive the acknowledgement of:
170 1 85 0
However, the relay may or may not really operate. Seems intermittent at best. Is it possible that there is contention between a 50msec poll and the relay commands?
Any thoughts on how we might poll at this rate with more consistent relay control/behavior? Thanks in advance…