Special "Measuring Only" Mode; Disabling Outputs - Siemens SIMATIC S7-300 Manual

Special operating modes of SM 335

5.3 Special "Measuring Only" mode

5.3 Special "Measuring Only" mode

Disabling outputs

If operating the special mode "Measuring Only" is set, SM 335 only measures the analog
inputs within the free cycle without updating the analog outputs. The analog outputs retain
their last analog value for a certain time in accordance with the number of active analog
inputs.
Number of active analog inputs
1
2
3
4
Note
• The watchdog is disabled while SM 335 performs continuous measurements. This state
• Interrupts are not generated in this operating mode (no diagnostics / process interrupts)
• A new analog value is output on expiration of the time.
purpose
You can use the special operating mode "Measuring Only" for high-speed successive
reading of the values from an analog input in order to obtain current analog values for a short
period of time (T
parameterized operating mode.
88
could prevent the detection of internal module faults.
<0.5 ms). After time has expired, SM 335 returns to the previously
A
Output of the updated analog after
Approx. 78 ms
Approx. 66 ms
Approx. 52 ms
Approx. 47 ms
SM 335 - High-speed analog mixed module for SIMATIC S7-300
Manual, 02/2009, A5E02409063-01