Owner's manual

35 M2 Rig Monitor Operator’s Manual
Recommended Modbus Wiring
The recommended Modbus wiring for the Rig Monitor is illustrated in Figure 12 below. In
this configuration, 5 wires are used for wiring the Rig Monitor into a Modbus system.
Figure 12 also illustrates typical alarm device wiring.
Figure 12: Recommended Modbus Wiring
Termination Jumper
The Rig Monitor includes a 2-pin termination header (see Figure 4) that is used when the
Rig Monitor is used in a Modbus system. Every Rig Monitor is supplied with a
termination jumper (a jumper block) installed onto this header. If the Rig Monitor is not
used in a Modbus system, this jumper has no function. When the Rig Monitor is installed
in a Modbus system, this jumper must be installed in an Rig Monitor that is at the end of a
Modbus line. Any Rig Monitor in a Modbus system that is not at the end of a line must
have the termination jumper removed (see Figure 13 & Figure 14 below).
Figure 13: Multiple M2 Rig Monitors in a Daisy Chain Configuration
C NC NO
-
24 VDC
Factory
Wired
+
S
PWR/SIG
FAIL
PWR/SIG
S
C NC NO
FAIL
To
Additional
M2s
Power
Converter
ALARM 2
A B C
RS 485 RS 485
A B C
ALARM 2
Input
Terminals
D1
D0
Power
Converter
Factory
Wired
24 VDC
-
+
Modbus
Controller
Common
C NC NO C NC NO
TOXIC OXY
C NC NO
ALARM 1
See
Detector
Wiring
See
Detector
Wiring
ALARM 1
C NC NO
TOXIC OXY
Modbus
Master
M2
Termination
Jumper
Installed
M2
Termination
Jumper
Not Installed
M2
Termination
Jumper
Not Installed
M2
Termination
Jumper
Not Installed
M2
Termination
Jumper
Not Installed
ID = 128
ID = 127 ID = 126 ID = 125 ID = 1
Up to 128 M2s can be connected without a repeater.
RS-485 RS-485