HORNER HE200WCM910, User Manual

Page: 13 / 56

RS ‐ 232/485 RF Modem Product Manual – MAN0782 ‐ 02 Page 13
RS-485 (4-wire) & RS-422 Operation
DIP Switch Settings & Pin Signals
Figure 2.10. Figure 2.11.
RS ‐ 485 (4 ‐ wire) and RS ‐ 422 Pins used on the female RS ‐ 232 (DB ‐ 9)
DIP Switch Settings Serial Connector
Figure 2.12.
RS ‐ 485 (4 ‐ wire) & RS ‐ 422 with Termination (optional)
Termination is the 120 Ω resistor between T+ and T ‐ .
DIP Switch settings are read and applied only while powering ‐ on.
Table 2.3. RS ‐ 485/422 (4 ‐ wire) Signals and their implementations with the RS ‐ 232/485 RF Modem
DB-9 Pin
RS-485/422
Name
Description Implementation
2 T- (TA)
Transmit Negative
Data Line
Serial data sent from the RS-232/485 RF Modem
3 R- (RA)
Receive Negative
Data Line
Serial data received by the RS-232/485 RF Modem
5 GND Signal Ground Ground
7 R+ (RB)
Receive Positive
Data Line
Serial data received by the RS-232/485 RF Modem
8 T+ (TB)
Transmit Positive
Data Line
Serial data sent from the RS-232/485 RF Modem
9 PWR Power
Optional power input that is connected internally
to the front power connector
1, 4, 6 not used
Wiring Diagram: RS-485 (4-wire) Half-Duplex
Figure 2.13. RS ‐ 232/485 RF Modem in an RS ‐ 485 (4 ‐ wire) environment