Videotec DCJ - Manuale (Pagina 155)

Page 23 MNVADCJ01_0543
4.13 Autotest o f serial channels
In the case of faulty operation or to check the keyboard, it is possible to carry out a simple test to make sure the
communication channels to the video device and the telemetry are working perfectly.
Disconnect any devices connected to the V, A and B lines and make up the following test cable, using two
telephone cables and two RJjack boxes supplied with the keyboard:
Phone cable RJjack 1 RJjack 2 Phone cable
RS485A white white RS485A
RS485B yellow yellow RS485B
Warning: this cable is different from the standard connection cable described in § 3.3 - Standard
connection cable, page 12.
4.13.1 Autotest pr ocedure
• Connect the cable to connectors A and B
• Connect the cable to connectors A and V
• Connect the cable to connectors B and V.
RRP
FOOOG
D''D
D
72,1+
The display shows FOOOG .
This means that input and output communication lines for the two
lines are functioning correctly.
RRP
OOOOG
D
D'D'
72,1+
Other types of message mean that the connecting cable is
incorrect or that the test lines are not working. In the example
channel A is able to transmit and B receives correctly, but
communication is only in one direction.
RRP
FOOOG
D
D
D
72,1+
The third line shows the results of the test: D , D and D stand
for the three lines - Video, Telemetry B and Telemetry A
respectively.
For each line, A, B and V, one of the following messages will be shown:
'' : the line is not working and is unable to transmit or receive data
' : the line is able to transmit but not receive
' : the line receives but is unable to transmit

: the line transmits and receives correctly.