© 2019 VPInstruments | MAN-VP-SPRO-EN | Revision: 1901 | Date: 04-07-2019
25
9
Electrical connections
NEVER USE AC POWER. THIS WILL VOID WARRANTY AND BRING PERMANENT
DAMAGE TO THE ELECTRONICS. THE INSTRUMENT MIGHT BE DAMAGED
BEYOND REPAIR.
CONNECT THE M12 CONNECTOR BEFORE POWERING UP THE INSTRUMENTS.
The VPFlowScope probe provides a 4 .. 20 mA / pulse output and a Modbus output. All signals are
present in the M12 connector. These outputs can be used to connect the VPFlowScope probe to a
building management system or energy monitoring system like VPVision.
Pin
Signal
Wire color*
1
+12 .. 24 VDC
Brown
2
0 Volt
White
3
4 .. 20 mA signal, active
Blue
4
RS485 B
Black
5
RS485 A
Grey
* Wire colors apply to VPInstruments cables
M12 5-pin female connector
Cabling
Shielded twisted pair cabling must be used for proper communication and measurement. Connect
shield to safety ground on one point. The thickness of the wires depends on the cable length. For
cabling below 300 meter | 1000 ft, use 20 awg. For longer runs use 18 awg or better.
Power supply
The input voltage is 12 to 24VDC. Make sure that the power supply is at least 12V at the connector.
Voltage drops will occur in long cables resulting in insufficient power. The display will notify you when
there is insufficient power.
9.1
4 .. 20 mA output
The 4 .. 20 mA output is an active, non- isolated linearized current loop that can be used to connect
the VPFlowScope probe to a control system, a building/processing management system or any 4 ..
20 mA based system.
There is one 4 .. 20 mA output available on the VPFlowScope probe. This output can be assigned to
one of the measurement parameters, only one can be selected. For each measurand, a number of
units is available. The factory default is m
n
/sec.
Measurand
Unit
Flow
m
n
/sec
Flow
m
3
n
/hr
Flow
l
n
/min
Flow
SCFM
Flow
m
3
n
/min
Flow
sfps
Pressure
bar
Pressure
psi
Temperature
°C
Temperature
°F