OPTICAL SYSTEMS DESIGN
DOC ID: 10104804.doc
OSD840 OPERATOR MANUAL
PAGE 13
2.3
OPERATION
2.3.1
OSD840T OPERATION
When using the OSD840T for the first time, check that the unit is in good condition with no
visible damage.
If a card version is used, insert it in an appropriate slot on the OSD chassis and check that the indicators
illuminate accordingly on power up. If a module version (OSD840C) is used, connect the unit to an
appropriate power source and check that the indicators illuminate accordingly on power up.
In either case take special note of the “Laser OK” indicator, it should be green. If it is red there may be
a problem with the laser. Disconnect power and have the Laser checked as soon as possible.
If RS485 data is required set the RS422/485 Mode switch to the “On” position, i.e. down (which is the
1st switch of the 4way DIPswitch. It is located on the Front Panel of Card Version and on the front of
the box in Case Version). Then toggle switches 2, 3 and 4 to set the RS485 Turnaround Delay to the
value appropriate to your system. If you are not sure of the correct value, leave all Turnaround Delay
switches “Off”, i.e. up. Refer to Table 6 for delay selection. As described in Table 3, RS485 is
available on Pins 2 (RS485+) and 11 (RS485-). If RS485 is not required, keep all four switches in the
“Off” position, i.e. up.
All ‘two wire’ RS485 devices are by default in receive mode, and only change to transmit mode for
data transmission. All RS485 protocols use a transmit delay to ensure successful transmissions to the
ends of the network. The delay is data rate and protocol dependent.
If RS485 is not required, keep all four switches in the “Off” position, i.e. up.
To connect a video signal, connect a BNC terminated coaxial cable from the camera to the unit. If the
camera is operational, the "Video Present" indicator should change from Red to Green.
Finally, plug in the optical connectors of the optical cable. If the remote OSD840R is connected, the
"Data Link" LED will change from Red to Green.
Plug the digital signal source and/or audio signal into the 26-pin D connector (DB26) on the rear of the
module.
Ensure that the correct signals are connected to the correct pins of Audio/Data Input/Output connector
as specified in Table 3.
TABLE 6: OSD840T/R RS-485 TIMING DELAYS
SWITCH COMBINATIONS
1
2
3
4
FUNCTION
DELAY
(
±
1%)
0
0
0
0
RS-422
N/A
1
1
1
1
RS-485
30us
1
0
1
1
RS-485
100us
1
1
0
1
RS-485
300us
1
0
0
1
RS-485
1ms
1
1
1
0
RS-485
3ms
1
0
1
0
RS-485
10ms
1
1
0
0
RS-485
30ms
1
0
0
0
RS-485
100ms
NOTE: Data Control Switch Settings for RS485 (0 = off, 1 = on)
