2 extended actuator signature, Extended actuator signature -9 – Yokogawa YVP20S User Manual

Page 135

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14-9

IM 21B04C50-01E

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<14. DIAGNOSTIC SERVICES>

14.3.2 Extended Actuator Signature

Extended actuator signature will measure the In-Out characteristics of the control valve in
the range defined by users. The total number of data is 100 points.

• Measurement Parameters

The input parameter is output pressure (Equal to MEAS_PRESS_AIR); and the output
parameter is the feedback signal ( Equal to FINAL_POSITION_VALUE.Value)

• Measurement Setting Parameters

The measurement setting parameters determine the condition of measurement. The
parameters consist of six float arrays. This group of parameters is shared with High Resolu-
tion Actuator signature.

Figure14.10 Extended Signature Setting

Lower Set Point[%]: lower measuring range, The valid range is -10 to 110%.

Higher Set Point[%]: higher measuring range, The valid range is -10 to 110%.

Recommended Scan Time [s]: Recommended Scanning Time.

Scan Time[s]: Scanning time. It determines the measuring time. User can use
Recommended Scan Time value as a guide to set the scanning time. The valid range
is 20 to 3600 sec.

Deviation margin[%]: Allowable deviation. The measurement is performed in
Proportional control algorithm. In this reason, deviation between the set point value
and the position value may occur due to the non-linear characteristic existing in the
control system. (Mainly valve hysteresis) Basically, this value dose not need to be
changed from the default value. But in case if stem position did not reach the desirable
point then increase this value or if stem position far exceeds the desirable point then
decrease this value to make the measurement correctly. The valid range is 0 to 500%.

Sampling rate[ms]: Sampling rate. This parameter is used for High Resolution Signa-
ture only. The valid range is 200 to 1000 ms.

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