Busting brain with logical operation

[jydepower 1]

Hallo all. Im strugling with some, what should be simple logical operation. I have a touch screen that logs data from the plc, when a tag goes from 0 to 1 or 1 to 0(i cant change this toggle type). Tag is called EnableLog and linked to a variable called EnableLog in the plc I want to start log when another variable called Data1 goes 1 > 0 So... Problem is when i reset Data1 to 0. The EnableLog sees thats as a toggle and does a second log. I think i have to somehow say: EnableLog for each time Data1 goes 1 > 0 Been trying to solve this for some hours now, but i cant solve it. Im using Gx iec developer with a q03 plc (ladder) The touchscreen is a EPC t190 with Ix developer. Hope anyone can help. Regards Martin

[kaare_t 155]

Use a PLS instruction (for rising edge triggering) or a PLF (for falling edge triggering). That will ensure to only send 1 pulse (note: a single pulse only) either on rising/falling edge.

[jydepower 1]

I have tried with PLS and no succes. Heres what happens: Data1 goes > 0 Then EnableLog goes 1 When EnableLog goes 1 the panel logs Data1 After a timer runs out (to make sure all data is collected) Data1 is reset to 0 When Data1 goes 0 EnableLog also goes 0, then panel logs again. So i get 2 logs for each log. One with Data1 > 0 and one with Data1 = 0 Hope this makes sense :)

[kaare_t 155]

So the problem is in iX and not in the PLC...!? What function(s) do you use for logging in iX?

[jydepower 1]

Under settings in Data logger i can choose between loggin within a time interval or on a tag event. So i choose tag event and put in the EnableLog tag. The manual says it will log when the tag goes either from 0 to 1 or from 1 to 0. If i could say each time it goes 1 it would be easy. But i dont see that option.

[kaare_t 155]

You'll need to add a custom expression. See picture.

[jydepower 1]

Oh. So i dont need to put in a tag under the settings menu?

[kaare_t 155]

You still have to use a tag

[jydepower 1]

Hmm pretty sure i did exactly like that. But it still logged when Tag1 turned back to 0. I dont need to put expressions on the Data tags i log right?

[jydepower 1]

Look what i found on Beijers website. Im gonna try that tomorrow. iX Datalogger - Double records for each log event When using the log once on tag connection, please mind that event will be fired (executed) on each "edge" false -> true and true -> false. Using an momentary signal will result in 2 log records for the same event. See below how to prevent that. Best Practice: Panels:Triggered by user, using a so called "Action", use "Toogle Tag" in "Controller" or even better the dedicated action "Log Once" found in "Others". PLC: Use following instructions FXxy-series: ALT (Alternate State) Q/L-system: FF (Flip-Flop)