TD 91684GB
16 April 2015 / Ver. G
Installation Guide
T942C and T942C/2 Central Unit
16
1.4.11 Relay Output for System Fault Indication
A relay output on connector J10 is used to indicate Central Unit malfunction and can also be
used to indicate system fault (e.g. system fault can be when a module drops out or reports
an error). Several parameters in the Central Unit software determine how the output is to be
used.
2
1
J10
T942C
RE02
3
2
1
S10B
Aux relay output
Figure 20. Relay output connector.
If the relay output is set to indicate system fault it is possible to use output 3 on connector
J12 to indicate Central Unit malfunction only, see the next section
As long as the Central Unit and system are operating properly the relay is actuated and has
a make-function.
NOTE: At power-up or restart of the Central Unit the relay is deactuated for about 20
seconds. If the relay is deactuated for more than 20 seconds either the Central Unit or
system is malfunctioning.
1.4.12 Central Unit Malfunction Output
If the relay output on connector J10 is used to indicate both Central Unit malfunction and
system fault then output 3 on connector J12 (screw 4) can be used to indicate Central Unit
malfunction only.
J12
4 OUT3
5 OUT4
6 GND EXT
3 OUT2 (CODE2)
1 +12V EXT OUT (CODE+)
2 OUT1 (CODE1)
Max load
100 mA
T942C
Figure 21. Connection of Central Unit malfunction only on pin 3 on J12.
The output capacity is max 100 mA and is of open collector-type, which means that to
produce a digital 12V signal a resistor must be connected between the output and +12V
(screw 1). If a digital signal is not wanted a relay can be connected between the output and
+12V.
As long as the Central Unit is operating properly the output is actuated.
NOTE: At power-up or restart of the Central Unit, the output is deactuated for about 20
seconds. If the output is deactuated for more than 20 seconds the Central Unit is
malfunctioning.
