FactoryTalk View Numeric Inputs

Liz · Oct 24, 2010

I have an existing FactoryTalk View SCADA that I need to add the equivalent of a bit momentary for a numeric input. In other words I need to be able to write a value to the PLC and have FactoryTalk View automacitally clear/zero it a few seconds later.

Does anyone know a method that will allow me to achieve this?

Operaghost · Oct 24, 2010

You didn't mention Machine Edition or Site Edition......

FactoryTalk View ME has Momentary pushbuttons and you can select a "value" type where pressing can send a specific value and releasing can send another value.

FactoryTalk View SE allows you to create a button object. For the action use a SET command in the PRESS ACTION field and then use a separate SET command in the RELEASE ACTION field.

OG

lostcontrol · Oct 24, 2010

Liz said:
I have an existing FactoryTalk View SCADA that I need to add the equivalent of a bit momentary for a numeric input. In other words I need to be able to write a value to the PLC and have FactoryTalk View automacitally clear/zero it a few seconds later.

Does anyone know a method that will allow me to achieve this?

Why does Factory Talk have to clear it, why not make the PLC clear it xx Sec later? This seems much easier in my book!

Liz · Oct 24, 2010

In an ordinary system, I would definately have the PLC clear the inputs. In this case, that is the more complicated option as the there are multiple Masters, telemetry and non-Allen Bradley hardware involved.

In response to OG's question, we are running FactoryTalk View Site Edition.

rdrast · Oct 25, 2010

How is it more complicated to have the PLC clear the input? All keypads write to the same address, yes?
Any time that register is non-zero, do your thing with it, and zero it out with logic in the PLC.

All versions of FTView have a serious lack, in that none provide any handshaking for numeric/string writes (even if you use the add-on functional numeric input control).

junior · Oct 25, 2010

I would create a momentary push button in factory talk view. The tag that you tie to it will only be high while the user is pressing the push button on the screen.

rdrast · Oct 26, 2010

junior said:
I would create a momentary push button in factory talk view. The tag that you tie to it will only be high while the user is pressing the push button on the screen.

And exactly how does this help with the original problem?

Steve Etter · Oct 26, 2010

Liz said:
I have an existing FactoryTalk View SCADA that I need to add the equivalent of a bit momentary for a numeric input. In other words I need to be able to write a value to the PLC and have FactoryTalk View automacitally clear/zero it a few seconds later.

Does anyone know a method that will allow me to achieve this?

The method I use for this is to have the keypad value written to a temporary register. When this register is anything other than zero, I write the new value to my working register. I then compare the working register to the temporary register and when they both match, I write zero to the temporary register.

This method allows any number of devices to write to the temporary register and then the moment the PLC sees a new value it is accepted in the working register and the temporary register is zeroed.

Steve

SMOKE · Oct 26, 2010

I would look different from what Liz is asking, but if you use a button, button you could write your variable on press or release, and add VB to zero it after one second.
If your only using a 1 and a 0 set a momentary PB to 1 second.

FactoryTalk View Numeric Inputs

Liz

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lostcontrol

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