Minimum And Maximum Values - Siemens Simatic ET 200SP Manual

Minimum and maximum values

10.1 Minimum and maximum values
Introduction
The AI Energy Meter HF determines the respective highest and lowest measured or
calculated value for a series of measured and calculated values. The values are stored
retentively in the module and can be read using measured value data records DS 144
(Page 237), DS 145 (Page 243), DS 154 (Page 239) and DS 155 (Page 245).
Benefits
Using the stored minimum and maximum values, for example, you can detect further
irregularities in addition to limit monitoring.
Calculation of minimum and maximum values
Minimum and maximum values are only calculated for the phases in accordance with the
configured connection type. Existing minimum and maximum values that have not been
calculated are assigned initial values. If faults such as under or overcurrent occur during
operation, new minimum and maximum values are calculated.
The measured and calculated values are initialized as follows during commissioning of the AI
Energy Meter HF so that the first calculation of minimum and maximum values supplies a
plausible result:
● Maximum values for measured and calculated values: Minimum values
● Minimum values for measured and calculated values: Maximum values
Minimum and maximum values are determined as "slave pointer procedures" from the start
of calculation. Start is effective as of activation of the function or after a reset. The module
uses the current actual value as the start value.
When you activate the parameter "Enable minimum and maximum value calculation gate",
the calculation only starts if the corresponding DQ bit ("gate open") was set (output data Byte
1, Bit 2 = "1"). You can stop the calculation at any time by deactivating the parameter or
closing the gate. Calculation starts again after reactivation. The gate for calculation of the
minimum and maximum values functions in the same way as the gate for energy meters.
Configuring
You configure the following settings in STEP 7:
● Enable calculation of minimum and maximum values
● Enable minimum and maximum value calculation gate
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Analog input module AI Energy Meter 480VAC/CT HF (6ES7134-6PA00-0CU0)
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Manual, 07/2018, A5E42674880-AA