Pin Descriptions-Rs/Eia-422/485 Mode - Microwave Data Systems MDS TransNET 900 Installation & Operation Manual

Pin Descriptions—RS/EIA-422/485 Mode
Table 20 lists the
operate in RS/EIA-422/485 mode. See
Table 20. DATA connector pin descriptions—RS/EIA-485 Mode
Pin Input/
Number Output
1 —
2 OUT
3 IN
4 IN
5 IN
6 --
7 IN
8 OUT
9 --
NOTES:
• RXD+/RXA and RXD–/RXB are data sent into the radio to be transmitted out
• RXD+/RXA is positive with respect to RXD–/RXB when the line input is a "0"
• TXD+/TXA and TXD–/TXB are data received by the radio and sent to the
connected device
• TXD+/TXA is positive with respect to TXD–/TXB when the line output is a "0"
4-WIRE CONNECTIONS
2
3
7
8
56 MDS TransNET 900 I&O Guide
connector pin functions for radios configured to
DATA
Pin Description
Not Used—Do not connect
TXD+/TXA (Received Data +)
Non-inverting driver output.
RXD+/RXA (Transmitted Data +)
Non-inverting receiver input.
Sleep (GND = Active)—A ground on this pin turns off most
circuits in the radio, including transmit, receive, modem, and
diagnostic functions. This allows for greatly reduced power
consumption, yet preserves the radio's ability to be quickly
brought on line. See Section 5.6, Using the Radio's Sleep
Mode (beginning on
Signal Ground (GND)
Connects to ground (negative supply potential) on the ra-
dio's PC board and chassis.
Not Used—Do not connect
RXD–/RXB (Transmitted Data –)
Inverting receiver input.
TXD–/TXB (Received Data –)
Inverting driver output.
Reserved for Special Uses (Do not connect)
RXD +
RXD –
TXD +
TXD –
Figure 22. EIA-422/485 Wiring Schemes
(Left: EIA-422, Right: EIA-485)
Figure 22 for wiring schemes.
Page 18) for details.
Invisible place holder
2-WIRE CONNECTIONS
2
3
7
8
MDS 05-2708A01, Rev. B
RXD+/TXD+
RXD–/TXD–