HGM-MZ to N2 Communications Adapter
8
Rev 1 (P/N 3015-5514)
9. Communications LED Indicators
The communications adapter board has four LED communications status indicators numbered 1-4. The
meanings of these indicators are shown below. See Figure 3 for the locations of the communications LED
indicators.
LED
Adapter
Function
Meaning When LED Is in the “ON” State
1
Tx
Adapter is transmitting a poll/command to the HGM-MZ
2
Rx
Adapter is receiving a response from the HGM-MZ
3
Tx
Adapter is transmitting a response to Metasys N2 (because poll/command was directed to this slave)
4
Rx
Adapter is receiving a poll/comm from Metasys N2 (directed to ANY N2 slave, not necessarily this one)
Under normal conditions, you would expect to see a lot of activity on LED 4 since the N2 master is continually
polling all N2 slaves on the line. LED 3 will show activity based on how often the N2 master is polling the
adapter (versus other N2 slaves on the line). If there are few N2 slaves on the line, a lot of polls will be directed
to the adapter and LED 3 will blink frequently and LED 3 will blink less frequently.
LED 1 and LED 2 will only show occasional activity. Since the refrigerant monitoring process is fairly slow
and new data is only available every 15 seconds or so, the adapter polls the HGM at a slow rate to reduce the
communications burden on the HGM main processor.
Figure 4 – HGM-MZ to Metasys N2 Adapter: Communications LEDs
