GE Industrial Solutions 6KCV301DGF - Manual (Page 58)

—————— Digital General Function Card —————— 58
GEI-100430
There is also the possibility to transition the DGF directly to RUN status at power-on.
For the READY to RUN transition the parameter to set is AB_RUN(504). To transition
the card into RUN status at power on set the parameter AUTO_RUN(508). To exit the
ALARM status(transition ALARM to READY) set the AB_RESALL(503) parameter.
Depending on your system requirements, configure these three parameters in the
appropriate way.
2.7.5 Working mode
The working mode of the DGF determines how and when the DGF starts the execution
of the user program or of the DeviceNet interface, when this is executed alone (from
now they are referred to as “period”).
You can configure:
1) how often to execute the period in the DGF;
2) whether the period can be started by the drive or cyclically by the DGF.
To set the source of the beginning of the period use parameter PERIODMODE(500).
Normal condition requires that the DGF starts the period with the drive.
To set how often the period will be executed, set the parameter PERIOD_TIM(501).
This must be a multiple of 2. You can read the effective value (a multiple of 2) in
parameter PERIOD_REA(502). To know the length of the maximum period, read
parameter REAL_TIME(512).
IMPORTANT: since the period has the highest execution priority internally to
the DGF, you must be sure to allow enough time for the
remaining services of the DGF (serial, fieldbus, dbase,
malfunction check, ...). For this reason the maximum value of
REAL_TIME must not exceed 2/3 of the value of
PERIOD_REA.
Depending on the period you have written, the period can take a longer or a shorter
time to be executed. This time is longer when you use complex blocks or many blocks
inside your period. So you must always set the appropriate period time in order to
optimize the use of the DGF.
To set the appropriate period time, you can do the following:
1)
Set PERIOD_TIM to 50msec (this is how often the period is started, for now
every 50msec)
2) Load the period and execute it
3) Look at PERIOD_REA after a certain time (this is the maximum time the period
took to be executed)
4) Set PERIOD_TIM to PERIOD_REA * 1.5, multiple of 2 (this is how often the
period is started, now with the optimized value)