Setting The Clock System - Siemens SIMATIC S7-1500 System Manual

Configuring
9.11 Configuring the clock system
9.11.6

Setting the clock system

The SIMATIC Drive Controller supports isochronous mode for the following clock systems:
• PROFINET IO interface X150
• PROFIBUS DP interface X126
• Technology I/Os X142
• SINAMICS Integrated with PROFIdrive Integrated (always isochronous)
You can operate the clock systems separately or coupled on an isochronous basis. Exception:
Isochronous coupling of the PROFIBUS DP interface is not possible. You can find information
on the combinations in which you can couple the clock systems in Overview of isochronous
mode (Page 197).
You make the required settings in the relevant clock systems.
Once you have set and, if necessary, coupled the clock systems, you need to couple the OB
servo with the clock system in which you wish to operate the drives / that is the leading clock
system. Depending on the configuration, these settings are made by the system.
Use of clock cycles < 500 μs
You can only use clock cycles < 500 μs in the CPU 1507D TF with the following restrictions:
• Limited quantities are available.
• The vulnerability for level overflows increases, for example, with MC Servo [OB91] and MC
Interpolator [OB92]. This may result in an involuntary STOP of the CPU, especially in case
of additional loads caused by the user program, traces and large watch tables.
• A down-scaling from the application cycle of the MC-Servo [OB91] to the selected clock
system, results in an additional load and should be avoided with small clocks.
You should, therefore, only use clock cycles < 500 μs in exceptional cases and test your
application very intensely.
For small position controller clock cycles, you can also use the position controller in the drive
(Dynamic Servo Control function, DSC). This allows for position controller clock cycles of
125 μs, for example.
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SIMATIC Drive Controller
System Manual, 11/2023, A5E46600094-AD