WAGO 750 Series Manual page 136

132 • Process Image
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Using predefined structures, it is possible to access the input or output process
image byte by byte via the following lines:
or word by word via the lines:
Before the input process image can be analyzed,
IOCTL_KBUSUPDATE,...)
image, it is also required to call
order to send the new values to the modules.
ioctl(iFD, IOCTL_CHANGE_UPDATE_SPEED, ulValue)
[ulValue from 1-10 is valid]
Used to set the polling interval to poll
. The default value is 3. This value can be reduced to 1 in order to
&ulTmp
achieve the highest possible speed of the application. However, this only
makes sense with very fast I/O modules and a very small user program.
The value can also be increased to 10 if only very slow analog I/O
modules are involved and fast updates of the process image are not
desired.
close(iFD)
Closes the KBus driver
pstPabIn->uc.Pab[byteNo]
pstPabOut->uc.Pab[byteNo]
pstPabIn->us.Pab[wordNo]
pstPabOut->us.Pab[wordNo]
ioctl(iFD, IOCTL_KBUSUPDATE,
must be called. After changing the output process
ioctl(iFD, IOCTL_KBUSUPDATE,...)
ioctl(iFD,
WAGO-I/O-SYSTEM 750
Linux Fieldbus Coupler
in