L-INX/L-GATE User Manual
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LOYTEC
LOYTEC electronics GmbH
Additionally, there is the possibility that also the network data points are already fixed or that
a given, user-defined interface is necessary. Then the developer has to connect the IEC61131
data points to the corresponding network data points by himself.
Finally, after downloading the configuration and rebooting the L-INX, the IEC61131
program can be downloaded to the L-INX via the Web UI or the L-INX Configurator. After
a final reboot the L-INX loads and executes the IEC61131 program.
8.6 Additional Features
8.6.1 Force Update Functionality
Per default the IEC61131 program only sends updates on changed output values. Every
program cycle the input values are fetched, the IEC61131 program is executed and the
calculated values are sent to the output driver. If the old values are identically with the new
one no updates are sent to the IEC61131 data points. As a result no update is sent to the
network.
For some applications, e.g. for a scene controller, it is necessary to send an update on request.
E.g. every time the input value is updated, the output value is forwarded to the network,
regardless if the value of the output value was changed or not.
For implementing this feature, special vendor blocks are available. First it is necessary to
check if there was an update on a selected input within the last execution cycle of the running
IEC61131 program. That functionality is offered by the function block
Update Notify
located in the StandardLibs
Loytec_Support folder. Second, an output must be forced to
send an update even if the value was not changed. The function block Force Update is used
for that functionality, it is located in the StandardLibs
Loytec_Support.
Figure 76: Force update
Figure 76 depicts how to use the force update functionality. Besides of the part of the
IEC61131 program that defines the calculations to perform (lower half of Figure 76),
additional logic for the force update functionality is required. The global input variable that
is monitored for changes is connected to the Update Notification function block. As a result,
the Boolean output ‘Updated’ is set to TRUE for one program cycle, if the value of the
connected variable has been updated since the last cycle start. To force the I/O driver send
out an update, the global output variable, which shall be updated, is connected to ‘Output’ of
the Force Update block. Hence, every time the ‘Update’ input of the Force Update block is
TRUE, the connected global output variable sends out an update at the end of the program
cycle.
Important:
Every global variable connected to the update notification or force update block must be
connected via the right-hand side terminal!
8.6.2 Using UNVT variables
Similar to the predefined CEA709 data types and the technology converter functions, user-
defined network variable data types can be used. The L-INX Configurator supports the
developer to generate the type definitions needed for UNVTs and enumerations based on
resources files. L
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