OPTICAL SYSTEMS DESIGN
OSD1250 OPERATOR MANUAL
PAGE 11
DOC ID: 10106110
2.4
DATA I/O CONNECTION
The OSD1250 Interface Card uses HDB26 connector. The data formats supported are RS232, RS422, RS485, and RS485 4-
wire.
Signal
RS232 Pin
RS422 Pin
RS485 Pin
RS485 4W Pin
GND PIN 1
1
1
1
1
TXD2
2
RXD2
3
RTS2
4
CTS2
5
DSR2
6
GND PIN 7
7
7
7
7
DCD2
8
DSR+
9
DTR-
11
DTR+
12
13 TX+
13
13 TX+
RXD+
14 RX+
14 RX+
RTS+
15
CTS+
16
DCD+
17
DSR-
18
485_4WR-
DTR2
20
485_2W-
21 TX-
21
21 TX-
RXD-
22 RX-
22 RX-
RTS-
23
CTS-
24
DCD-
25
NET ERROR
26
26
26
26
TABLE 3: DATA I/O CONNECTION
For RS232 without anti-streaming five connections are required being TXD2, RXD2, GND.
DSR2 needs to be connected to DTR2 if the user equipment does not generate DTR.
All modes support NET ERROR as an open drain output.
