Measuring Only" Mode - Siemens SIMATIC SM 335 Manual

Special SM 335 Operating Modes
5.3

"Measuring Only" mode

Deactivating outputs
In "Measuring Only" mode, the SM 335 measures only the analog inputs in the free
cycle and does not update the analog outputs.
The analog outputs retain their old analog value for a period of 40 to 60 ms.
• When measuring at one analog input: 60 ms
• When measuring at 2 to 4 analog inputs: 40 ms.
Note
• While the SM 335 is measuring, the watchdog is not active.
This makes it impossible to detect any internal module fault.
• Interrupts are not generated in this mode (no diagnostics or hardware
interrupts).
• A new analog value is output after the time expires.
Purpose
You can use "Measuring Only" mode to read values from an analog input in rapid
succession and thus obtain, for a short time, the most current analog values
(T < 0.5 ms). After the time expires, the SM 335 returns to the previously parame-
A
terized operating mode.
5-14
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1