WIKA GDM-RC-100-T Betriebsanleitung Seite 22

5. Commissioning, operation
5.4.1 Connection assembly (model GD-20-D)
Use a cable consisting of shielded twisted pair data lines with suitable characteristics for
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the particular operating conditions.
Select a cable diameter that matches the cable bushing of the connector or the cable
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EN
socket. Make sure that the cable gland of the fitted connector or fitted cable socket has a
tight fit and that the seals are present and undamaged. Tighten the threaded connection
and check that the seal is correctly seated, in order to ensure the ingress protection.
Make sure that no moisture enters at the cable end
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5.4.2 Pin assignment of attached, digital transmitter (model GD-20-D)
Circular connector M12 x 1 (5-pin)
1
2
3
4
5
5.4.3 Pin assignment, integrated, digital transmitter (model GD-20-D)
Via 4-pin terminal in the cable socket, conductor cross-section 0.205 ... 2.5 mm
4-wire terminal in cable socket
5.4.4 Requirements for shielding and grounding
Only use shielded cables and connect the shield on one side to the read-out unit.
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The gas density sensor is grounded via the process connection of the mechanical
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base instrument.
Ensure that no earth circuits can occur.
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5.4.5 RS-485
The physical layer for the Modbus
EIA/TIA-485. The differential signal between pins 4 and 5 (A and B) is evaluated with a
2-wire system (half-duplex).
22
- -
U Supply voltage
+
U Ground
-
A Signal RS-485
B Signal RS-485
U DC 10 ... 30 V
+
U Ground
-
A RS-485 signal
B RS-485 signal
protocol is the serial RS-485 interface per
®
WIKA operating instructions, model GDM-RC-100-T
2