Optical Systems Design OSD8826 Series, Operator'S Manual

Page: 10 / 20

OPTICAL SYSTEMS DESIGN
DOC ID: 10110306
OSD8826 OPERATOR MANUAL
PAGE 10
2.3
PIN ASSIGNMENTS AND CONNECTIONS
Pin assignments for the “Data Input/Output” connectors (Figure 3) are shown in Table 3 below. The
module versions and single channel cards have the 8 way cage clamp terminal block connector while
the 2 channel receiver card version has two RJ45 connectors.
TABLE 3: PIN ASSIGNMENT
PIN FUNCTION PIN FUNCTION
1
Data Input +
5
RS232 Input
2
Data Input –
6
RS232 Output
3
Data / RS485 2W DI/O+
7
Contact Closure
4
Data Output - / RS485 2W DI/O-
8
Data Ground
RS485 2-Wire
half duplex is used to connect several devices to the same bus when only one unit
transmits data at a time. All units are normally in high impedance receive mode waiting for data. When
transmission of data is requested, the unit waits for a protocol specific turn-around time delay before
transmitting after which it returns to receive mode.
RS485 4-Wire
full duplex is used for master/slave arrangement. Devices are polled and respond faster
with no turn-around time delay required between request/response. The receiver is always enabled
allowing the devices to receive data even while responding to a request.
Note:
If a link doesn't seem to be working correctly, try swapping the polarity of the data lines on both
ends. Some devices are marked opposite the RS485 standard.
RS422 / 4W RS485
Pin Connection
1 Rx +
2 Rx –
3 Tx +
4 Tx –
8 Ground
2W RS485
Pin Connection
3 I/O +
4 I/O –
8 Ground
Contact Closure
OSD8826T
Pin Connection
7 Contact Input
8 Ground
OSD8826R
Pin Connection
7 Normally open (NO)
8 Common (COM)