Specifications

Multi-Zone Gas Monitors
P/N: 3015-5074 Rev 10 15
Use any of the remaining service knockouts to gain access to the interior of the monitor. The RS-485
communications wiring between the MZ and RD must be connected in the following manner:
1. Locate the RS-485 connector in the MZ (see Figure 2-3 on page 13).
2. Connect one lead of a twisted shielded pair to the “B” connection point. Note the wire color.
3. Connect the second wire to the “A” connection point. Note the wire color.
4. Connect the ground to the “
GND
” connection point.
5. Locate the RS-485 connector marked “TO MONITORS” in the RD (see this topic in the RD manual).
This connector is located on the bottom of the RD PC board, second from the right.
6. Run the wire to the RD and connect the twisted shielded pair to the RS-485 “TO MONITORS”
connector using the same color code as used on the MZ.
2.5.2. Integrating with Building Management Systems
The MZ may be connected directly to a Building Management System using a shielded twisted pair cable.
The cable from the Building Management System is connected to the RS-485 connector inside the MZ
monitor. MODBUS RTU is the standard communications protocol.
Use any of the remaining service knockouts to gain access to the interior of the monitor. Locate the RS-485
connector 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.
2.5.3. Larger Integrated Systems
You may also connect the MZ monitor to a Building Management System through a Remote Display. In this
case, first connect the MZ to the RD as described above. Then, follow the instructions in the
Communications Connections section of the RD manual for information on how to connect the RD to a
Building Management System.
Figure 2-6. RS-485 Connector
2.5.4. Changing Terminator Switch Settings
The terminator switch is shipped from the factory in the “OUT” position (no termination). This is the correct
setting if the MZ is to be installed in the middle of a network. If the MZ monitor is connected as a single
device or if it is the last device on the network chain, the terminator must be moved to the “IN” position.
Locate switch #4 and determine its position. If it must be moved, slide the switch to the appropriate position.
(Note that switches 1-3 are for service use.)