Isochronous Mode - Siemens ET 200SP Manual

4.2.7

Isochronous mode

The technology module supports the "Isochronous mode" system function. In isochronous
mode, the output sequence starts at time T
The period duration is also adapted to the application cycle (T
The synchronization is especially advantageous for setting up control loops.
The module adjusts the assigned value of the period duration in such a way that an integer
ratio results. In the most unfavorable case, the difference amounts to half the application
cycle.
Examples:
Application cycle
The figure below shows an example of a 1:1 ratio of application cycle to period duration with
a duty cycle of 50%.
The figure below shows an example of a 3:1 ratio of application cycle to period duration with
a duty cycle of 50%.
Technology Module TM Pulse 2x24V (6ES7138‑6DB00‑0BB1)
Manual, 05/2019, A5E35061186-AB
Assigned period duration
T
APP
10 ms
(10000 μs)
after the SW_ENABLE control bit has been set.
o
Actual period durationT
T
Setpoint
1800 μs
2000 μs
3000 μs
5000 μs
6000 μs
12000 μs
16000 μs
Configuring/address space
4.2 Pulse width modulation PWM mode
) and synchronized with it.
APP
Actual
1666 μs
2000 μs
3333 μs
5000 μs
5000 μs
10000 μs
20000 μs
T :T
APP Actual
6:1
5:1
3:1
2:1
2:1
1:1
1:2
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