Technical Specifications

ValVueFF Software Interface to FVP
138
GE Energy
Signature Tab
The Signature function is a component of the diagnostic function (Figure 117). This
function protects the valve from degradation failure and reports on the condition of the
control valve or the positioner by comparing the history of signature characterization. To
accomplish this objective a positioner must have the ability to measure and retain data
describing the characteristics of the control valve and the positioner.
Figure 117 Signature Tab - Diagnostic Dialog Box
Measurement procedures for signature of the control valve and the positioner force the
control valve to move the stem position; thus the measurement procedures must be
performed while the process is off line and the device is in Out of Service state.
ValVueFF used with the /BP (pressure) option has the ability to store locally, the standard
actuator signature data. When connected to ValVueFF, using the Diagnostics window, the
valve signatures can be retrieved from ValVueFF non-volatile memory and compared to
the current valve position, output pressure and other process information with valve
signatures to determine if there is a change in system performance.
The ValVueFF with /BP option supports six types of user signature functions:
❑ Measure All: Measures all of the other five.
❑ “Standard Actuator Signature” on page 149: Static characteristic of the control
valve.
❑ Extended Actuator Signature: Extended static characteristic of the control valve.