Intek RheoVac DR - Manual (Page 12)

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Figure 8 4-20 mA Output Circuit
Figure 9 Optional Transmitter Box
TABLE II. Optional 4-20mA Configuration
Channel Output Parameter
1 Actual Volume Flow
2 Total Mass Flow
3 Water Vapor Flow
4 Pressure
5 Water Vapor to Air Mass Ratio
6 Relative Saturation
7 Air Mass Flow
8 Temperature
C. Transmitter Box (optional, See Figure 8) - For driving eight (8) remote 4-20 mA analog
signals from one RS-485 input port. Note: Intek recommends using the network connection
for all data transmissions and RheoVac communications.
1. Connect the RS-485 communications/power cable from the distribution box (RS-485:
white and blue wires; 24Vdc power: red and black wires).
2. Connect up to eight (8) signal wire pairs to the indicated terminals for isolated 4-20mA
outputs.
3. Figure 8 provides the RheoVac DR wiring detail for the 8 channel 4-20 mA outputs.
Table II provides the appropriate connection identification. Transmitters are configured
as active (transmitter sources the current) when shipped. To change to the passive mode
(receiver to source the current), extract each small 4-20 board, find the JP1 pins, and
move the two jumpers from the "Act" pins to the "Pass" pins (two positions to the right
of factory settings). Figure 9 shows the current output circuit. The figure also illustrates
the active mode and the passive mode configurations.