Rockwell Automation 1503VC IntelliVAC Plus Contactor Control Module - Manual (Page 147)

9-24 DeviceLogix
1503-UM054C-EN-P – June 2013
Add a digital output point (DOP)
In order to add an output tab click the “Bit Output” button. Clicking
the button will add an input tag to the top left of the logic currently
being displayed. The user is then permitted to move the tag to the
desired location. Alternatively the user can click the “Bit Output”
button, hold the mouse button depressed and drag the new tag onto
the screen in the desired location. Once the tag has been added
double clicking the tag will display a drop down box with the
available output bits which can be assigned to the tag.
Bit Negation
It is possible to Negate a bit (change from a “1” to “0” and vice
versa) without the use of a “NOT” gate. This allows the user to
minimize the number of gates used, and keep the interface screen
less cluttered. In order to negate a bit right click on the line
connecting the output of one element to an input of another. Upon
clicking the line a drop down box will appear with three options
“DELETE”, “ASSUME DATA AVAILABLE”, and “NEGATE”.
Select negate. A circle will appear a around the connection line to
indicate that it is negated.
Figure 9.12 – Bit Negation
Assume Data Available
There are some cases in which the logic is executed in a loop and the
DeviceLogix compiler cannot determine the execution order of the
function blocks. During these cases, the user must manually
determine the execution order.
In order to identify situations where this must be done use the logic
verification tool. If there is a loop in the newly created logic an
error message will be displayed upon logic verification. If this is the
case the loop which cannot be compiled will be displayed in orange.
Follow these steps to resolve the error:
1. Rick click the orange connection. A pull down menu will be
displayed.
2. Chose “Assume Data Available”. This will cause the connection
to execute first.
3. Use the logic verify tool to ensure that the logic will now execute
correctly.