Matrox Design Assistant's Quick Comm feature provides a
handshake protocol between the runtime platform and the PLC.
Reaching certain points in the flowchart trigger actions, which
make up the handshake protocol, as outlined in the
Status and control handshake subsection of the Procedure for
communicating with controllers section earlier in this chapter.
With Quick Comm, the data fields that are associated with the
handshake actions are predefined. However, Matrox Design Assistant
also allows you to create custom actions and events and associate
them with data fields.
Matrox Design Assistant also allows you to define events that
trigger the execution of a given flowchart upon a change in value
of a certain data field.
The following steps provide a basic methodology for configuring
a custom subflowchart event that is based on a data field:
-
Open the
Platform Configuration dialog, and then navigate to the
Profinet or
EthernetIP page under the Industrial
Protocols page, depending on which industrial protocol you
are using.
-
Click on the plus button in the top-right
corner of the appropriate module. Each module contains a set of
data fields. The Status and Control modules, as well as
each Camera
module, contain the data fields that are predefined by Quick Comm.
The DataFromPLC
and DataToPLC
modules contain custom data fields to be written by or read from
the PLC.
-
Select the data field to associate with the event, and click on
Add Event, which
will open a dialog.
-
Specify the value to which the specified data field must change
to execute the subflowchart. You can set the subflowchart to
execute when the field changes to any value, or to a specific
value. You must also select the flowchart to execute upon the
change in value. You can either select a flowchart from the list,
or create a new flowchart by clicking on the plus button.
-
Once you have created an event, you can delete it or modify it.
You can modify the data field value that triggers the flowchart
execution, as well as the flowchart to be executed.
Note that you cannot change the field associated with an event.
To do this, you must first delete the event, and create a new one.
Also, a given data field cannot be associated with more than one
subflowchart execution event.
Matrox Design Assistant allows you to define custom PLC
handshake actions. These event-triggered actions can set or clear
the value of a data field, or wait for a certain value in a data
field. This is useful when modifying the default handshake (for
example, if you wanted to delay the project ready signal from
triggering, until after some equipment is initialized).
The following steps provide a basic methodology for creating a
PLC handshake action:
-
Open the
Platform Configuration dialog, then navigate to the
Actions page
under the Industrial
Protocols page.
-
Click on the Add
Action button.
-
You will then be prompted to choose the event which will trigger
the action. Select the appropriate event from the list
presented.
-
An action entry will be added to the list in the Actions page. Configure the
following settings for the new action entry:
-
Action. This
is the actual action which will be triggered by the chosen event.
Possible PLC handshake actions are Set, Wait, and Clear.
-
Condition.
This is the condition which must be satisfied to perform the
action. You can set a condition value to True, False, None (no condition), or a
user-defined expression (for example, Status.Result=Pass).
-
Module. Each
module contains different data fields. The Status and Control modules, as well as
each Camera
module, contain the data fields that are predefined by Quick Comm.
The DataFromPLC
and DataToPLC
modules contain custom data fields to be written by or read from
the PLC.
-
Field. This
is the data field on which the action will be performed.
-
Value. This
is the value that the specified field will be set or cleared to, or
the value that will be waited for in the specified field. For
predefined data fields, you can set the value to either
True or
False. For data
fields in the DataToPLC module, you must
specify a user-defined value.
-
Once you have created an action, you can change the event that
triggers it, disable it, or delete it, by clicking on the
appropriate button in the top-right corner of the
Platform Configuration dialog.