Siemens SIMATIC ET 200S Operating Instructions Manual page 267

Modulation of the Pulse Duration
The 2PULSE calculates the pulse duration on the basis of the output value you set (between
0 and 1000‰):
Pulse duration = (output value/1000 [‰]) x period.
Minimum Pulse Duration and Minimum Interpulse Period
The minimum pulse duration and minimum interpulse period are superimposed on the
proportional output characteristic.
You assign the minimum pulse duration and minimum interpulse period using the
Minimum/Pulse duration parameter; they always have the same value.
A pulse duration calculated by the 2PULSE that is shorter than the minimum pulse duration
is suppressed.
A pulse duration calculated by the 2PULSE that is longer than the period minus the minimum
interpulse period is set at 1000‰.
Figure 5-7
You specify the period in accordance with the required accuracy of the process variables
generated by the actuator.
Setting Times Using a Time Base
You use the assignable time base to select the resolution and range of the period, the
minimum pulse duration and the on-delay.
Time base = 0.1 ms:
Time base = 1 ms:
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
Modulation of the Pulse Duration
You can set times from 0.2 ms to 6.5535 s with a resolution of 0.1 ms.
You can set times from 1 ms to 65.535 s with a resolution of 1 ms.
2PULSE
5.3 Modes and Functions
267