Vaisala hmdw110 series, Quick Manual, Page: 12 / 108

Component Board
All HMDW110 transmitter models use the same component board, which has 2 output types:
Modbus mode (RS-485) and analog mode (current output). The output type is selected when
ordering the device. See the type label of the device to see the chosen output type.
The component board has also a service port for configuration and calibration use.
8 T-
7 T+
6 HUM-
5 HUM+
4 Pwr+
3 Pwr-
2 RS485-
1 RS485+
Servic
e
Port
1
2
3
Figure 4 HMDW110 Series Component Board
1 Terminal block for 4 ... 20 mA current loop outputs. Must be disconnected when the
transmitter is powered through RS-485 connection in the lower terminal block (terminals
1 ... 4).
2 Service port connector (4-pin M8)
3 Terminal block for RS-485 output. For Modbus or RDP100 remote display panel
connection.
You can pull out the terminal blocks from the component board for easier
installation, and to disconnect the transmitter from power and RS-485 when using
the service port.
Before using the transmitter in Modbus mode, always disconnect the terminal
block for terminals 5 ... 8 to prevent the effects of ground loop on measurements.
The RS-485 connector used for Modbus communication in the lower terminal
block will power the transmitter.
12 M211692EN-C