9XTend-NEMA RS-232/485, Руководство по эксплуатации продукта

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9XTend ‐ NEMA™ RS ‐ 232/485 RF Modem – Product Manual v2.x4x [2007.01.04]
© 2007 MaxStream, Inc., Confidential & Proprietary ‐ All Rights Reserved 11
2.3. RS-485 (4-wire) & RS-422 Operation
2.3.1. DIP Switch Settings and Pin Signals
2.3.2. Wiring Diagrams
Figure 2 ‐ 13. XTend RF Modem in an RS ‐ 485 (4 ‐ wire) environment
Table 2 ‐ 03. RS ‐ 485/422 (4 ‐ wire) Signals and their implementations on the XTend RF Modem
DB-9 Pin
RS-485/422
Name
Description Implementation
2 T- (TA)
Transmit Negative
Data Line
Serial data sent from the RF modem
3 R- (RA)
Receive Negative
Data Line
Serial data received by the RF modem
5 GND Signal Ground Ground
7 R+ (RB)
Receive Positive
Data Line
Serial data received by the RF modem
8 T+ (TB)
Transmit Positive
Data Line
Serial data sent from the RF modem
9 PWR Power
Optional power input that is connected internally
to the front power connector
1, 4, 6 not used
Figure 2 ‐ 10. RS ‐ 485 (2 ‐ wire) Half ‐ duplex
DIP Switch Settings
Figure 2 ‐ 11. Pins used on the female RS ‐ 232 (DB ‐ 9)
Serial Connector
Figure 2 ‐ 12. RS ‐ 485 (2 ‐ wire) w/ Termination
(optional)
Termination is the 120
Ω
resistor between T+ and T ‐ .
DIP Switch settings are read and applied
only while powering ‐ on.