GE Industrial Solutions 6KCV301DGF - Manual (Page 23)

23 —————— Digital General Function Card ——————
6KCV301DGF
2.1.4.1 Initialization of the General variables
Each General variable (IVAR, FVAR and NUM) is combined with the attribute Init
Level stating the rule with which these variables are initialized by the firmware.
This attribute can have the following values:
Firmware
The variable initialization and control is carried out by the standard
firmware and the user has no possibility to intervene
Persistent
The variable initialization value can be modified by the final user and it
is stored in the DBASE. This variable is initialized with a value set at the
card start.
Retentive
The initialiation value is set during the program developing phase. The
final user CAN NOT modify the initialization value but he can modify
the variable value after the initialization. The variable initialization is
carried out during every transition from the IDLE to the READY
condition.
Volatile
The initialiation value is set during the program developing phase. The
final user CAN NOT modify the initialization value but he can modify
the variable value after the initialization. The variable initialization is
carried out during every transition from the READY to the RUN
condition.
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2.1.4.2 Data management inside the DBASE
Each parameter that has been put up from DBASE is identified through a unique
identifier, called IPA. Furthermore, for each parameter, predefined or general, a data
record is associated that regulates the behavior of the parameter in the different phases
of the program. The detailed description of the fields of this record will be made in
another paragraph but the functions which are conditioned by this record are the
following :
- Initialization at power-on
- Access to the parameter from the external world.
- Parameter storage
- Display of the parameter on the keyboard of the Drive.
2.1.4.3 Access to a parameter from the external world
The external world can access a parameter to perform one of the following operations:
- Parameter reading
This operation is always possible independent from the DGF status. The parameter is
normally returned in the size specified by the attribute TYPE.