MDS 05-2708A01, Rev. D
MDS TransNET I&O Guide
71
Pin Descriptions—RS/EIA-422/485 Mode
Table 28
lists the
DATA
connector pin functions for radios configured to
operate in RS/EIA-422/485 mode. See
Figure 23
for wiring schemes.
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 the TXD– / TXB when the line output is a “0”
Invisible
place
holder
Figure 23
.
EIA-422/485 Wiring Schemes
(Left: EIA-422, Right: EIA-485)
Table 28. DATA connector pin descriptions—RS/EIA-485 Mode
Pin
Number
Input/
Output
Pin Description
1
—
Not Used—Do not connect
2
OUT
TXD+/TXA—Non-inverting driver output. Supplies data to
the connected device.
3
IN
RXD+/RXA—Non-inverting receiver input. Accepts data
from the connected device.
4
IN
Sleep—A ground on this pin turns off most circuits in a Re-
mote radio, including transmit, receive, modem, and diag-
nostic functions. This allows for greatly reduced power
consumption, yet preserves the radio’s ability to be quickly
brought on line. See
“Using the Radio’s Sleep Mode (Re-
mote Units Only)” on Page 59
for details.
5
--
Signal Ground (GND)—Connects to ground (negative sup-
ply potential) on the radio’s PC board and chassis.
6
--
Not Used—Do not connect
7
IN
RXD– /RXB—Inverting receiving input
8
OUT
TXD– /TXB—Inverting driver output.
9
--
Open (User configurable via internal jumper. See
“User Configurable I/O Connections” on Page 72
)
2-WIRE CONNECTIONS
4-WIRE CONNECTIONS
TXD +
RXD +
2
3
7
RADIO
DA
T
A
CONNECT
OR
8
RXD –
TXD –
EXTERNAL
DEVICE
RXD –
TXD +
RXD +
TXD –
RXD+/TXD+
2
3
7
RADIO
DA
T
A
CONNECT
OR
8
RXD–/TXD–
EXTERNAL
DEVICE
RXD –
TXD +
RXD +
TXD –
Содержание TransNET 2400
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