Limit Monitoring; How Limit Monitoring Works - Siemens Simatic ET 200SP Manual

Limit monitoring

9.1

How limit monitoring works

Introduction
The AI Energy Meter HF supports monitoring of parameterizable low or high limits for up to
16 analog measured or calculated variables.
You can also specify multiple limits for each measured or calculated variable, in order to
define a high or low value range.
The measured value data record 150 returns the current status of limit violations and one
counter per limit that displays the number of limit violations. In addition, a hardware interrupt
may be generated for each limit violation.
The status of the limit violations can also be evaluated in the user data variant 240 (F0
via the user-defined user data variant or the user-defined data record via the measured
value ID 65509.
Benefits
With activated limit monitoring you can already detect any irregularities in the measured
value acquisition already in field level.
Retentivity
All the counter states are stored retentively in the AI Energy Meter HF. After an interruption
(e.g. Power System Off), the counting resumes with the retentively stored values.
Configuring
You configure the following limit monitoring settings in STEP 7:
● Measured variable that is to be monitored.
● Activate / Deactivate limit monitoring.
● High or low limit values.
● Delay time and hysteresis for each limit.
● Activate / Deactivate hardware interrupts at limit violation.
● Measured value that is subject to limit monitoring.
Analog input module AI Energy Meter 480VAC/CT HF (6ES7134-6PA00-0CU0)
Manual, 07/2018, A5E42674880-AA
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