Additional Information about Each Function (continued)

Averaging

Exclusivity If averaging and filtering are both enabled, alarming is

 

exclusive of averaging. This means that after the data is filtered it is

 

compared against alarm setpoints and then averaged.

 

Numerical Range Values loaded into the module for averaging are

 

expressed as 16-bit unsigned integers 1 to 65535 in units of number of

 

samples. Signed integers will be interpreted as unsigned values.

 

 

 

 

NOTE: A value of zero is ignored and the default value of 20 is used if zero is

 

loaded and enabled.

 

 

 

Averaging Reset Y27 is used to reset all 16 channels to begin the averaging process again. The previously loaded averaging sample number is used (or the default value of 20 if no data is loaded) and the averaging function is enabled.

 

Averaging Reset with New Value

In the event a very large number for

 

averaging is inadvertently loaded into the module and enabled, the input

 

channel will appear to not be working correctly. The input channel requires

 

a reset with a smaller number of samples. To initate a reset with a new

 

averaging value, the number of samples is loaded as previously described

 

and then each channel may be individually reset and enabled for the new

 

value with WY75.

 

 

Peak and Valley

Peak or valley hold data is returned in locations WX49 ± WX64, provided

Hold

that Y30 and Y31 are set accordingly. See Figure 3-14.

 

 

 

 

 

Data Read

Y30

Y31

 

Peak

1

1

 

Valley

0

1

 

Flags

X

0

 

 

 

 

Figure 3-14 Peak/Valley Truth Table

NOTE: Upon power up and the enabling of peak and valley hold, peak values returned will be the actual value at input. Valley values must go below zero, which is the default value before data is returned. This is not the case if a reset is issued to the valley function. On reset the valley threshold is the current value.

3-22 Advanced Function Programming

SIMATIC 505±2557 Installation and Operation Guide

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Siemens 505-2557 installation and operation guide Averaging, Peak and Valley, Hold