RSView/FactoryTalk View Momentary Help

What I want to do is this, have a momentary push button whose output value depends on another tag. For example if you press this button when pump A is on it will output '4' to the PLC and if you press this button when pump B is running it will output a '2' to the PLC. Once you release the button it writes a '0' to the PLC (the momentary part).

FactoryTalk View has it's own momentary buttons, however, the problem I have with them is that the "Value" is set to a "hard" number; you can't say be one value in this instance and another number for that instance.

I went down the macro route but I found out that all of expressions in a macro are done at the same time; so you can't write to the same value twice in the same macro. Because I can't write to the same value twice I can't reset the output value to zero (the momentary thing).

Any help? I want to keep all of the logic in the panelview if possible.

Ouch. I don't even know if it's possible to write "2" when the button is held, and then "0" when it's released let alone multiple values when the button is held, based on the state of other inputs.

How about writing the logic into the PLC? Then the "momentary" button is just a trigger for a PLC subroutine that compares the current state of the inputs, writes a value based on those inputs, and then clears that value when the PB is released.

You could consider placing two momentary pushbuttons in the same spot and use the visibility (under the animation parameters) to determine which button can be pressed.
For example if bit variable for motor 1 was Motor1ON the expression in the visibility tab would be MotorON = 1 ... motor 2 would be Motor2ON = 1.
But, this would pose a problem if both motors have the possibility of being on at the same time.

seneal said:

You could consider placing two momentary pushbuttons in the same spot and use the visibility (under the animation parameters) to determine which button can be pressed.
For example if bit variable for motor 1 was Motor1ON the expression in the visibility tab would be MotorON = 1 ... motor 2 would be Motor2ON = 1.
But, this would pose a problem if both motors have the possibility of being on at the same time.

Click to expand...

Heh. Yeah, I thought of that too. And I've done it. But it gets really unwieldy if you get to more than 3 of whatever it is you're messing with. And, in this case, you wind up with a bunch of auxiliary tags somewhere to track the combined states of all the possible inputs so that you can turn Visibility on and off. Also, I still don't know about writing one value on button down and then clearing it on button up, altho that sounds like something a macro or script should be able to do.

I know that the OP wanted to keep it in the HMI, but maybe this is one of those times that the PLC is a better place. Unless he doesn't have access to the PLC... then, I'd guess he would have to write all the necessary aux logic in the HMI and play with multiple buttons that are visible at the correct times.