16 Channel I/O Board 4
Man-1170EN Rev.01
Additional Boards Installation Manual
16
Inputs
•
Inputs to the I/O board are optically isolated and are activated by connecting any of the terminals marked
0V to the input via a contact with a resistance no greater than 500 ohms. The current switched by the
contact will be a maximum of 3 milliamps. The figure below shows an example input situation.
Figure 4-2
Example Input
Outputs
•
When configured as outputs, the I/O board channels supply a negative voltage (with respect to the I/O
board 24V power supply) via a transistor.
•
Because transistor elements can be damaged by excessive current drain, great care should be taken
when connecting to outputs. Particular care should be taken to ensure that suppression diodes on relay
coils are correctly polarised. Wrongly connected diodes will damage the outputs. Diodes should be
connected with the band to the positive 24V.
•
Individual channels can supply current up to 100 milliamps but this must be limited to 500 milliamps for
each bank of eight (500 milliamps for 1-8 and 500 milliamps for 9-16).
•
The power supply to the I/O board should also be considered to ensure that its rating is not exceeded if
multiple channels are switched on.
Figure 4-3
Example Outputs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0V
Contact wired
to operate input
Channel 3
3 milliamps (Max.)
Main Back Board
Field Terminals
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
24V
2K2
100 milliamps (Max.)
Example relay connection
Example LED connection
Polarity of suppression diode
is very important. Wrong conection
will damage output.
Relay coil resistance greater
than 300 ohms.
Main Back Board
Field Terminals
24V
