Because of the high total current consumption of the digital I/O modules (from
UP = 24 V DC), the supply is divided up into several electric circuits fused
separately.
The maximum permitted total current over the supply terminals of the I/O ter-
minal units is 8 A.
The total current can be calculated as follows:
I
Total
= I
L+
+ I
UP
with the assumptions
I
L+
= I
CPU
+ I
I/O bus
+ I
C1
+ I
C2
+ I
C3
+ I
C4
(CPU + communication m I/O bus)
I
I/O bus
= Number of expansion modules × Current consumption through the I/O bus per module
and
I
UP
= I
UP1
+ I
LOAD1
+ I
UP2
+ I
LOAD2
+ I
UP3
+ I
LOAD3
+ I
UP4
+ I
LOAD4
+ I
UP5
+ I
LOAD5
+ I
UP6
+ I
LOAD6
+ I
UP7
+ I
LOAD7
If one assumes that all outputs are switched on and are operated with their maximum permitted
load currents (under compliance with the maximum permitted currents at the supply terminals),
then the following values are the result for an example shown above:
Application planning
Power supply dimensioning > Calculation of the total current consumption
2023/03/03
3ADR011074, 1, en_US
27