Connecting the Inputs and Outputs of the SM 335
2-8
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
Cable
There is a voltage drop on the cable between SM 335 and the linear potentiometer.
Because of the SM 335’s high resolution, this can play a role in the measuring of
the analog signal. You can compute the voltage drop on an electric cable as fol-
lows:
U
+
r
0
· I · L
A
U: Voltage drop along the cable
r
0
: Resistivity of the cable used
(for Cu: 0,0172
W
mm
2
/m)
I: Current flowing through the cable in
amperes
L: Length of the cable in meters
A: Cross-section of the cable in mm
2
Because of this, we would recommend keeping the cables as short as possible
and using a cable with the largest possible cross-section.
