Siemens SIMATIC S5 ET 200U - Signal Sequence for Up-Counting

9-24
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
The sensor signals to the module inputs must satisfy the following require-
ments:
 Signal sequence for up–counting
t
1
tt
tt
t
2
Sensor
Signals:
V
a2
V
a0
V
a2
t
1
Figure 9-13 Signal Sequence for Up–Counting
 Pulse time of the sensors
5 V Sensors 24 V Sensors Pulses
t w500 ns w10 ms V
a1
= Position decoder count pulses (A)
t
1
w2 ms w40 ms V
a2
= Position decoder count pulses (B)
t
2
w500 ns w10 ms V
a0
= Position decoder ref. pulses (R)
 Minimum edge steepness
Voltage
Description Minimum Edge
Steepness
5 V Differential signals according to RS 422A
(A, A–N, B, B–N, R, R–N):
5 V / ms
24 V Count pulses and reference pulse
(A, B, R):
0,3 V / ms
24 V Enable and reference signal: 0,3 mV / ms
Function Modules