
SymDec 4
User Manual
10
RS232 Port
The RS232 port is provided for external control of the SymDec 4 from a PC via the PC’s serial port. This
requires the use of a DB9-F to DB9-F null modem cable (or DB25-F depending on the type of RS232 port on
the PC).
Camera Inputs
There are two BNC jacks for each camera. Either jack can receive a camera signal. The signal is looped
(directly connected to the other jack), making the camera signal available to other equipment.
The camera input connectors are auto terminating.
This means that the input signal will automatically be terminated with 75-Ohms unless a 2
nd
cable is connected
to the 2
nd
BNC connector of the same camera input. Make sure there is 75-Ohm termination at the end of the
video line if the signal is looped through the SymDec 4.
Time base correction is performed during digital capture. As a result, cameras do not require synchronization.
Table 7.
RS232 port pinouts
Pin
Use
1
DCD
2
RX
3
TX
4
DTR
5
Grounded
6
Not connected
7
RTS
8
CTS
9
Not connected
Cable
75-Ohm coaxial
Connectors
BNC
Auto terminating
Yes
Passive looping
Yes