BRUEL & KJAER VIBROCONTROL 8000 - 9.4.2 RCM (Secondary) Buffered Output Connector; 9.5 Analog (4-20 mA) Output

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VC-8000 MPS
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9.4.2 RCM (Secondary) Buffered Output Connector
The RCM buffered output connector provide secondary access to
buffered analog signals from all UMM modules.
This connector is rarely used and is limited to just 10 ft. (3 m)
maximum. It is preferred to use the RJ-45 connector on the UMM.
Contact B&K Vibro technical support for the connector pinout
(if needed).
NOTE
Generally, it is more convenient to use the
buffered output RJ-45 connector on each UMM to
route the buffered signals to a permanent patch
panel.
9.5 Analog (4-20 mA) Output
Each UMM/TMM has analog outputs corresponding to a designated measurement selected in the
configuration software. 4 mA corresponds to the configured bottom-scale, 20 mA corresponds to the
configured full-scale. The 4 to 20 mA is self-powered (sourcing) and requires no external power
source.
For example, the following table shows a radial vibration channel with a range of 0-5 mils (0-125 µm).
Radial Vibration Channel Analog Output
Fault
2.0 mA (if 2mA clamp is enabled)
0 mils (0 µm)
4.0 mA
1 mil (25 µm)
7.2 mA
2 mils (51 µm)
10.4 mA
3 mils (76 µm)
13.6 mA
4 mils (102 µm)
16.8 mA
5 mils (127 µm)
20 mA
Table 9-1) Analog output (4-20 mA) examples
Historically the DCS would use this signal to drive annunciation relays and/or trips and to show the
values on operator viewing screens.
Today the use of analog signals (4-20 mA) is less common. Most customers now use the VC-8000
system itself to drive relays and/or trips, and the operator screens get their data from a Modbus
communications link.
Wiring analog signals adds cost to the project; costs for wiring the signals and the hardware cost for
the input cards at the DCS. Again, Modbus is a more efficient way to send data to the DCS for
visualization.