I am wishing to control the velocity at which a table is turning. I currently have a line study that is steered by signals and am turning my table through a simple device operation. Of course I could vary the duration of the operation to make the process appear slower/faster, but that's not achieving my purpose.
From reading other posts I gathered the notion that the actions tab of the Resource LB Editor can be used to control some more advanced movements.
I am seeking clarification as to when the actions of the ResourceLB (Move to Pose, Joint Velocity Controlled etc.) are executed?
What is the meaning of the Value Expression field for the actions?
My idea was to use a key signal (type REAL) to be used as the velocity expression for the Move to Pose action for the table. The help manual only states that some of these features are new but does not adress how to use them. Some directions for the use of the actions tab is greatly appreciated.
Solved! Go to Solution.
Value Expression is any expression that gives a signal to the action, to perform this action with the give settings/parameters below.
So the action is executed when the expression becomes TRUE.
In this case value expression is just a LB entry (Bool):
Also Joint value expression is a LB entry (Real):
You can do also something like this: "entry1" AND "entry2" AND NOT "entry3".
For acceleration/deceleration you can do e.g. calculations "entry1" * 1000
Thanks for the clarification. So the value expression box has the same function as for regular exit signals, which makes sense. I was irritated of the presense of IF-Expression in the exit signals.
I have implemented a similar structure as your example. As you can see from the screenshots, I would like to use a key Signal to control the angular velocity at which my device turns. I would also like to pass the target position for my device to turn to through the signal TargetPos (type WORD).
Currently I can not enter any string for signals of type WORD, I am guessing I will need to represent the letters of the desired position in integers so that PS can read them?
Also, do I still need an exit signal or will the actions be invoked as soon as the Value Expression is true automatically?
Except for the Value Expression which is a Boolean, all other values are REAL values.
If your target value is a WORD you could convert it yourself or type it in to the Velocity, for which PS will usually cast it into a REAL automatically.
The action is invoked when the VALUE EXPRESSION is TRUE and the JOINT VALUE EXPRESSION does not equal the current joint value (assuming velocity and acceleration are not zero. If they are the action is triggered but nothing will move of course).