Digi ConnectPort X4 IA Quick Start Manual page 14

PV Temp #1:
PV Temp #1 Shield: Cable Shield and Drain
Connecting RS-485
The PV -100-2 is supplied with a half duplex RS-485/422 serial port. The default
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firmware build supports RS-422 only. Custom firmware builds are addressable and
support integration into RS-485 networks. Contact RainWise for further information.
Wiring connections are made using the 4-pin screw terminal inside of the PV
electronics enclosure. Cable is not supplied with the unit. The RS-485/422 lines are
terminated with a 120 ohm resistor. This can be disabled by moving the termination
jumper, located inside the unit, to the OFF position. This requires removing the enclosure
cover. To do this, remove the 4 screws on the bottom side of the unit.
RS-485/422 Terminals
A (-) :
B (+) :
Gnd:
Shield:
RS-485 is rated to 4,000 feet (1,200m) at 90 kbps. The RS-485 port on the PV
is surge protected but not isolated.
Connecting the Power Supply
The power supply is nominally rated for 24VDC but can accept a voltage in the range of
10 to 30VDC. The inputs are reverse polarity, surge, overvoltage and over current
protected. The power supply is not isolated.
Power Supply Terminals
Earth Gnd:
Gnd:
24VDC:
Connectivity Verification
Once the station is completely connected, the power supply should be turned on.
When power is applied, the red "Health" LED should start flashing. This LED is the
system's heartbeat and indicates proper functionality. If the "Health" LED is solidly lit or
off, RainWise Inc. should be called for further troubleshooting.
The TX and RX LEDS are used to indicate when the station is transmitting, (TX), or
receiving, (RX), data over the modbus line.
Signal
Negative RS-485
Positive RS-485
Signal Ground
Cable Shield and Drain
Earth or Chassis Ground
Negative Supply Voltage
Positive Supply Voltage
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-100-2
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-100-2
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