VEGA WHA-GW-WIRELESSHART GATEWAY - Manual (Page 29)

WHA-GW-*
Installation
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Connecting to RS-485
1. Unscrew the 4 screws of the housing cover (see Figure 3.6 on page 23).
2. Remove the housing cover.
3. Route the STP cable through the first cable gland from left at the bottom of the Gateway
housing (see Figure 2.5 on page 17). The permissible cable diameter lies between
6 ... 10 mm.
4. Connect the STP cable to the first terminal block labelled "RS485" (see Figure 3.11 on
page 28) according to the following table.
5. For a daisy-chain connection, route the second STP cable through the second cable
gland from left at the bottom of the Gateway housing. Connect the second STP cable to
the second terminal block labelled "RS485" according to the following table.
6. To activate the RS-485 termination, set DIP switch number 7 to "ON" (see Figure 6.4 on
page 67).
7. Screw the housing cover to the housing again.
8. Tighten the cable gland with appropriate torque (see table "Installation torque cable
glands" on page 32).
The Gateway is now connected to the RS-485 network. The yellow RS-485
communication status LED starts flashing when a correct HART or Modbus protocol
message is received (see chapter 6.1).
Gateway wiring (RS-485 connection)
Note!
Tension relief and bending radii
Ensure sufficient relief of tension on the cables during installation and note the minimum
bending radii of the cables.
Note!
If the cable shield is grounded, the grounding should only be connected to one end of the
cable, in order to avoid equipotential bonding currents.
Wire RS-485 cable Terminal WHA-GW Meaning
RxD/TxD - (RS-485 A) A RS-485 differential signal
RxD/TxD + (RS-485 B) B
Shield SHD Cable shielding