Emerson ROC827 User Manual
Page 107

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
:
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.