MDS 05-4846A01, Rev. H
SD Series Technical Manual
27
COM2 PORT NOTES:
•
RXD+ / RXB and RXD– / RXA are data sent to the radio to be transmitted
• RXD+ / RXB is positive with respect to RXD– / RXA when the line input is a “0”
• TXD+ / TXB and TXD– / TXA are data received by the radio and transmitted
• TXD+ / TXB is positive with respect to the TXD– / TXA when the line output is a “0”
Invisible place holder
Figure 21. RS-485 Wiring Arrangements
EIA-485 2-WIRE CONNECTIONS
TXD
RXD
2
3
7
RADIO
DA
TA
CONNECT
OR
8
RXD +
TXD +
EIA-422 4-WIRE CONNECTIONS
RXD/TXD
2
3
7
RADIO
DA
TA
CONNECT
OR
8
RXD+/TXD+
EXTERNAL
DEVICE
EXTERNAL
DEVICE
RXD +
TXD
RXD
TXD +
RXD +
TXD
RXD
TXD +
This jumpering must be provided by user.
