The input/output of the Parallel interface are photocoupled.
According to the voltages applied to the inputs, it is necessary to adjust the value of the
resistance R (Figure 1) to obtain the nominal input current IF.
The emitted signal must be positive in relation with its earth.
Example :
TP
+ signal coming from the detection cell
CTP
−
signal coming from the detection cell
Figure 1 :
Diagram of a photocoupled input
3
4
Protection diode
On the Industrial Interface card
15
Photocoupler
Photocoupler LED
TOPEXT
−
16
17
18
14
0 VA
+ 24 VE
0 VA
N˚ of Terminals
Detection
cell
Figure 1
Parallel link - Presentation
A13862 Version E
Page 7-5