Emerson MSM400 manual Terminal Label Function

4.6ELECTRICAL CONNECTIONS

All field wiring connections are accessible by removing the lower lid, which is secured by two screws. Note that it is the responsibility of the installer to observe all local regulations and approval requirements, and to use cable to suit the environmental requirements of the particular application. Obtain and check any hazardous area work permits required before applying power to the MSM400.

The diagram below shows the layout of external connection terminals: all terminal blocks are suitable for wires 0.5mm2 to 2.5mm2 (26-12 AWG). Insulation should be stripped back 7mm.

Ensure wiring is suitable for the load current and the insulation is suitable for the voltage, temperature and environment of the installation.

Note that in intrinsically safe systems, apparatus connected to the MSM400 must not be supplied from a voltage greater than 250V rms or 250V DC.

FUSE 200mA

K7941

Figure 9: Connection Terminal Layout

Note that not all of the labelled terminals are functional in this version of the MSM400. The functions available are listed below :

CONNECTION DESCRIPTIONS :

Terminal	Label		Function
1	RX	A	Sensor Cable
2	RX	B	Sensor Cable
3	RX	SCN	Screen for 1+2
4	TX	SCN	Screen for 5+6
5	TX	A	Sensor Cable
6	TX	B	Sensor Cable
7	TRIGGER 0V		Ground ref for Trigger inputs
8	TRIGGER D1		Digital input No 1
10	TRIGGER 5V		5 V output
16	I out Io		Current output (4-20mA)
17	I out 0V		Current output zero ref terminal
18	I out 24V		Current output 24 V DC loop power : refer to Fig. 10
19-21	RELAY 1		NC-C-NO Relay output	terminals for Relay 1
22-24	RELAY 2		NC-C-NO Relay output	terminals for Relay 2
25	DC out 24V		Output of 24 VDC for powering external devices.
26	DC out 0V		Ref for DC output
27	DC in 24V		Positive supply at 24VDC to the MSM400--ie DC power input
28	DC in 0V		Ref terminal for DC supply input
29	Mains L		AC power input 115/230V, Live terminal		NB: SELECT 115 or 230V
30	Mains N		AC power input 115/230V, Neural terminal		ON SWITCH ABOVE
31	Mains E		Protective Earth (PE)		THESE TERMINALS

NOTE 1 The sensors are symmetrical, so either of the two cable pairs can be chosen as "Tx" or "Rx

IP258

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