Specifications

Halogen Gas Monitor – MultiZone Remote Display
Instruction 3015-5157 14
Communication Connections
HGM-MZ Network
The HGM-RD is connected to the HGM-MZ using a shielded twisted pair instrument cable. The maximum
distance between the furthest away HGM-MZ and HGM-RD is 4500 feet.
Use any of the remaining service knockouts to gain access to the interior of the monitor. The RS-485
communication wiring between the HGM-MZ and HGM-RD must be connected in the following manner:
Locate the RS-485 connector in the HGM-MZ (Page 16 of HGM-MZ manual 3015-5074). Connect one
lead of a twisted shielded pair to the “B” connection point (the far right point), note the wire color.
Connect the second wire to the “A” connection point (the middle), note the wire color. Connect the
ground to the “GND” connection point
Locate the RS-485 connector marked “TO MONITORS” in the HGM-RD (Page 12). This connector is located
on the bottom of the HGM-RD PC board, second from the right. Make the wire run to the HGM-RD and
connect the twisted shielded pair to the RS-485 TO MONITORS connector using the same color code as
used on the HGM-MZ.
Integration with Building Management System
A second RS-485 connector inside the HGM-RD allows a Building Management System to “talk” to the HGM-
MZ network through the HGM-RD. The connection is established using a shielded twisted pair cable.
Use any of the remaining service knockouts to gain access to the interior of the HGM-RD. Locate the RS-485
connector marked “TO HOST” (Page 12) and remove it from the circuit board. Secure the wire leads to the
connector orienting them as shown in the diagram below. Check to make sure that the polarity matches the
wiring to the Building Management System. When you are through securing the connections, carefully plug
the connector back onto the circuit board.
RS-485 Connector