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Emerson ROC827 User Manual

Page 107

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ROC827 Instruction Manual

Issued Mar-06

Communications

5-15

Figure 5-6. MVS Jumper J4 (Shown Not Terminated)

Four wires run from the MVS module terminal block and connect to the
sensor. The wires should be a minimum size of 22 AWG and a maximum
length of 1220 m (4000 ft).

Note

: Insulated, shielded, twisted-pair wiring is required when using MVS

signal lines.

Two of the terminal blocks provide power and the other two terminals
provide a communication path. Table 5-16 identifies the terminals.

Table 5-16. MVS Signal Routing – Comm3, Comm4, and Comm5

Label MVS

LED

Terminal

A

RX / TX +

Lit green when receiving

1

B

RX / TX –

N/A

2

None

No Connect

Lit green when transmitting

3

+ Sensor

Power

N/A

4

– Common

N/A

5

Notes

:

ƒ Pay close attention to the connections; do not reverse the power

wires. Make these connections only after removing power from the
ROC827. Double-check connections for the proper orientation before
applying power. If the connections are reversed and power is applied,
you will damage both the MVS module and the ROC800-Series
processor board.