65-2670-XX-04 M2A Transmitter Operator’s Manual
13
Power/Signal Terminal Strip
The power/signal terminal strip is a three position plug-in style terminal strip located at the top of the
left terminal column. It is used to connect 24 VDC power to the M2A and to connect the 4 - 20 mA
output signal to a device.
The signal output, the S terminal, does not have to be connected for the M2A to function. The S
terminal is used if you want to connect the 4 - 20 mA output signal to another device such as a gas
monitoring controller, chart recorder, or programmable controller (PLC).
Detector Terminal Strip
The detector terminal strip is a four position plug-in style terminal strip and is the middle terminal strip
in the left terminal column. The two terminals labeled “TOXIC” are used to connect the detector to the
M2A.
NOTE:
The detector is factory-wired to the M2A. See “Wiring the M2A Transmitter” on page 18
for all wiring procedures related to M2A.
Modbus Terminal Strip
The Modbus terminal strip is a three position plug-in style terminal strip and is the bottom terminal
strip in the left terminal column. It allows connection of the M2A into a Modbus network.
Relay Terminal Strips
The right column of terminal strips consists of, from top to bottom, the fail, alarm 1, and alarm 2 relay
terminal strips. They are three-position plug-in style terminal strips. The relay terminal strips are used
to connect devices such as lights and horns that are controlled by the relay contacts. The relay contacts
are rated at 115 VAC, 5 amps. The relay contacts may also be used to control higher rated relays.
Figure 4: Terminal PCB Component Location
C
N
C
N
O
AL
A
R
M
1
C
N
C
N
O
AL
A
R
M
2
C
N
C
N
O
FA
IL
Modbus Terminal Strip
Ground Jumper
Programming Connector
(Factory Use)
Termination Jumper
Relay
Terminal
Strips
RS
4
8
5
A
B
C
-
S
+
PW
R
/S
IG
+
Ribbon Cable Connector
Power/Signal Terminal Strip
Detector Terminal Strip
T
O
X
IC
O
X
Y
+
