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Chapter 8: RS-485 Modbus Output
65-2662XL-04 M2A-XL Transmitter
Ground Jumper
The M2A-XL includes a 2-pin ground header (see Figure 4 on page 13) that is used when the
M2A-XL is used in a Modbus system. Every M2A-XL is supplied with a ground jumper (a
jumper block) installed onto this header. If the M2A-XL isn’t wired into a Modbus system or if it
is wired into one as shown in Figure 12, the ground jumper should be installed. If the M2A-XL is
wired in a Modbus system as shown in Figure 11, the ground jumper should be removed.
Recommended Modbus Wiring
The recommended Modbus wiring for the M2A-XL is illustrated in Figure 11 below. In this
configuration, 5 wires are used for wiring the M2A-XL into a Modbus system. Figure 11 also
illustrates typical alarm device wiring. The ground jumper must be removed in this wiring
configuration.
Figure 11: Recommended Modbus Wiring
Adding an M2A-XL to an Existing M2 Modbus Installation with
Recommended Wiring
An M2A-XL can be wired into an existing M2 Modbus system. The shape of the terminal PCB
will be different but the wiring connections are identical and the ground jumper on the M2A-XL
must still be removed.
-
S
+
+
PW
R
/S
IG
PW
R
/S
IG
+
-
S
+
RS
4
8
5
A
B
C
A
B
C
RS
4
8
5
+
-
10-30 VDC
Input
Terminals
Modbus Controller
Remove Ground Jumper
Power Supply
Common
D1
D0
+
C
NC
N
O
AL
A
R
M
1
C
N
C
N
O
AL
A
R
M
2
C
NC
N
O
FA
IL
See
Detector
Wiring
C
NC
N
O
AL
A
R
M
1
C
N
C
N
O
AL
A
R
M
2
C
NC
N
O
FA
IL
To
Additional
M2As
Remove
Ground
Jumper
TO
X
IC
O
X
Y
+
TO
X
IC
O
X
Y
See
Detector
Wiring
