Trouble modifying existing Medoc program for FX2n

[wilcox101]

I have very little experience with Mitsubishi logic and I need to modify an existing program from 1999. I am looking for some insight on how to approach this request. The required change has to have Y035 energize 2x during one scan of the program. (Double stroke the cyclinder) FX2n PLC Y035 connected to a spring return solenoid GX Developer 8.20W (Originally coded with Melsec Medoc 16bit) M855 M630 -------| |------------------------------------------------| |-------------------------------------------------------------------------------------(M857 ) MAN MECH | PWR ON EXT MECH TEST | CYL | | | M645 M860 M760 | ------| |------------|/|------------| |-------------| CYC OK INDX2 OK INDX1 START RET M857 M858 M859 M630 ------| |------------|/|------------|/|-------------| |-------------------------------------------------------------------------------------------(Y035 ) EXT MECH TST OK TST FAIL PWR ON MECH CYL CYL RET RET EXT I can upload source code if anyone is interested. Any suggestions would be greatly appreciated!

[Sergei Troizky]

A scan is one pass of cyclic execution of the code by PLC. Physical outputs (Y) are being refreshed only once per scan, more specifically- between scans. Typical scan period is 5-10 milliseconds. Even toggling once per scan will not be properly executed by a solenoid valve, not to mention a cylinder. Did you probably mean activating the cylinder twice under the same conditions? Edited March 29, 2015 by Sergei Troizky

[wilcox101]

My apologies for misspeaking. Yes when the conditions are met to energize that output I need to have it activate 2x...Extend-Retract-Extend-Retract.

[JRoss]

What is the current operation? The code looks a little garbled in my browser. Could you post a screen shot or (better yet) the actual program?

[Sergei Troizky]

????(T1) ? T1 ?? ??(T2) ? T1 ??/??(Y35) ? T2 ? ?? ?? T1 is the 1st stroke duration. T2 is the valve off time between the strokes.

[wilcox101]

Here are the Melsec Medoc files that I am working with. Step 2772 is where the logic starts for moving the "plunge cylinder". Thanks in advance to all who look at this code for me. T000044A-BYRNE.zip

[Sergei Troizky]

I already gave you a solution. Just replace the timers with any presently unused ones.

[wilcox101]

Sergei, thanks for the help. I will deploy this change today after production has finished for the day. After this is done I will give all an update to the change made. Thanks again for your insight and help!

[wilcox101]

Sergei your solution has proven to be very effective. A little timer tweaking and I am up and running as requested! Thanks for the help.