For an HMI button to work in both auto and manual is a little tricky in many projects.  The reason is that while in auto, corrupting the normal process state by forcing a certain output on or off can put the system into an unknown or unforeseen or unhandled state.

Once in a bad state, it is often difficult to recover.

That said, perhaps the output is blinking on the HMI to indicate Auto mode override is activated to alert you to the potential bad state.  Check for the button attributes / animations to see if it is supposed to blink in auto mode (a fair precaution).

yordcherv

Dear 0_Einstein,

Thank you very much for your advises.

I've solved all the problems except one that I can't figure out why it's happening.I work with a touch panel and use two mutually exclusive blocks to activate the outputs of the PLC - Automatic FB and manual FB.But when I activate an output with the manual block, the graphic on the touch panel that depicts the active output is correct, while the searching output, but activated with the automatic FB, causes the same graphic to blink.If you have any idea or experience with a similar problem I would be happy to hear your solution.

With kind r5egards,

Yordan Chervenkov

Check in the inactive FB for logic that needs to be RESET before enabling full system function for the active FB.

It is generally better to have FBs always run, but skip over logic that is not needed.

In this process, we generally find / fix / redesign the blocks to properly initialize, operate, and reset, and to only operate when "enabled" by a specific (user define) ENABLE input rather than the global block EN input. 

yordcherv

Dear 0_Einstwin,

Thank you for your letter.

1. " ... an HMI button to work in both auto and manual ..."

It is not one button for manual and automatic mode. Manual mode is selected with one button, and automatic mode with another.

And one output, depending on whether it is controlled in manual or automatic mode, is included in the program in different FBs. So if one FB - manual mode is active, the output is controlled by the FB for the manual mode , and the auto mode FB is inactive end not executed.

2. " ... Check for the button attributes / animations to see if it is supposed to blink in auto mode (a fair precaution)... "

I checked. They are not in that mode. I didn't design them to blink in the first place.

With kind regards,

Yordan Chervenkov

As a quick check for your logic actions, insert a simple "counter" of the number of PLC scans the HMI bit is on, how many times the physical output changes state, and see how you are resetting the HMI input in the PLC logic (rather than waiting a LONG time for the user at the HMI to release the button and hopefully deactivate the request).

Or, is this HMI button an override button that keeps the output ON the entire time the button is pressed?

Knowing how the button is expected to operate is important.  However, using simple INC1 instructions to count the number of times the PLC is required to act on the HMI button press is helpful.  I generally find it helpful to react in logic ONCE, reset the HMI request, and then hold the request on until the opposite action is requested from the HMI.

Like an ON button, and an OFF button on a manual override screen, rather than having a single button do both.

It does depend what operators, techs and engineers are generally used to doing in the rest of the existing equipment, if there is a purchase spec requirement for a specific type of button action (toggle, ON-while pressed, OFF-while released, or 2 buttons (1-off, 1-on)).

Make sense?

yordcherv

Dear 0_Einstein,

Thank you for your answer.

1. " ... Check in the inactive FB for logic that needs to be RESET before enabling full system function for the active FB... "

Ans: I checked and additionally enabled networks for the inactive FBs

2. " ... In this process, we generally find / fix / redesign the blocks to properly initialize, operate, and reset, and to only operate when "enabled" by a specific (user define) ENABLE input rather than the global block EN input... "

Ans:

I checked one more time. All Blocks operates by a user define specific ENABLE input.

Unfortunately, however, the effect with the graphics flashing in the HMI remains !

With kind regards,

Yordan Chervenkov

The TON timer DBs must be unique throughout the project.  You can review all the uses of timer DBs in "System blocks" in the project tree.  Right-click on each TON timer and verify the TON block exists in only one block (FB/FC/OB).  Fix any duplicates.

If you need FBs to have TONs, use INSTANCE TON timers rather than Global DB TON timers.