GE Industrial Solutions 6KCV301DGF - Manual (Page 18)

—————— Digital General Function Card —————— 18
GEI-100430
The execution cycle of the above-mentioned two tasks is fixed through a parameter
and can vary from 2 to 20 milliseconds with a tick of 2 milliseconds. The reason the
execution time of these important tasks is variable is that the TASK PERIOD carries
out the program developed by the user, and is dependant on the size of the custom
application program. A later chapter explains how to choose a correct execution time.
TASK MEDIUM This task executes code with medium importance; in the futu-
re parts of the user-developed program will be allowed to
execute in this task. The execution time is fixed at 50
milliseconds.
TASK ASYN DPRAM This task in the applications code executes with the drive for
the parameters at low priority, using the structure ASYN
DPRAM of the DPRAM. The connection is carried out
asynchronous from the regulation task of the drive.
TASK POLLING This task carries out checks of very low importance. The
execution time is fixed at 500 milliseconds. The DGF interacts
with the external environment through two devices:
DRIVE DGFCy Can read and write some parameters of the drive and through
these modify the working of the drive. Moreover, the DGF
has the ability to manage directly the physical I/O of the drive.
For additional information, refer to section 2.1.7.
I/O CARDS If the physical I/O of the drive is insufficient for the application
it is possible to add additional optional cards with specific
functions. Further information is given in their respective
documentation.
The DGF operation can be configured through DGF parameters. The access from the
external world to these parameters is managed by the DBASE. The DBASE is a set of
procedures and data which coordinates and manages the access to DGF parameters.
The DBASE is the interface between the operating system of the DGF and the external
world. The devices which can access the DBASE
of the DGF are the following:
-
Serial port RS-485 of the DGF in modality SLINK2, SLINK3 and SLINK4
- Serial port RS-232 of the DGF in modality SLINK2, SLINK3 and SLINK4
- Serial protocol DeviceNet
- Drive keypad from the application card or Opt 2 menu
- Optional communication cards on the drive
- Serial port RS-485 of the drive in modality SLINK3 for DGF
Further information regarding the DBASE is given in section 2.1.6.