A C-more panel can lock itself after idle time with no PLC. Set SYS COUNTREPEAT on and SYS COUNTINTERVAL to 1000 for one count per second, switch to the password screen when SYS COUNTVALUE passes 1800 for a 30-minute timeout, and reset SYS COUNTMAX to 0 from button presses.
A C-more panel can lock itself after 30 minutes of idle time with no PLC in the cabinet. The system tags give you a counter that steps once per second while SYS COUNTREPEAT is on, and one event in the event manager switches the display to your password screen when the count passes a threshold. Button presses reset the count. The settings below come from a working build on an EA9-T15CL wired directly to a motor drive, where the panel is the only controller there is.
Why the screensaver cannot lock the panel
The screensaver blanks the display, and the first touch returns to the screen that was open before it started. No system tag turns on when the screensaver activates, so the event manager has nothing to trigger on. Give the screensaver the job of dimming and nothing else; setting the HMI backlight saver timeout controls when that happens. If all you need is the panel falling back to its opening screen after idle time, returning an HMI screen to home after 10 minutes idle covers that with the same event manager. A password gate needs the switch built here.
What you need
- The screen number of your lock screen. Open the project and read the number the software assigned it. The switch action writes this number, so a wrong number sends the operator to the wrong screen.
- A confirmed password gate on that screen. Switch to it by hand and check that machine actions stay blocked until the password is entered. Do this before you automate anything, and keep your password recovery path open while you commission.
- The event manager in the C-more programming software.
- The lock screen as the startup screen, so the panel opens on it at power-up; setting the HMI startup screen is where that setting lives.
The events, in order
- Arm the counter at power-up. Create one event triggered by SYS BIT ON with two actions: set SYS COUNTREPEAT to ON and set SYS COUNTINTERVAL to 1000. In this build the value steps once per second.
- Restore the ceiling. Create an event triggered by SYS COUNTVALUE = 0 whose action sets SYS COUNTMAX to 2000. With repeat on, the count climbs to 2000 and rolls back to zero on its own; this event puts the ceiling back after every reset.
- Switch on timeout. Create an event triggered by SYS COUNTVALUE > 1800 whose action writes your lock screen number to the "switch to screen number" tag. If the lock screen is screen 2, the action writes the constant 2.
- Reset on activity. For each pushbutton that should count as activity, create an event triggered by its press with the action set SYS COUNTMAX to 0. The ceiling drops to zero, the count rolls back with it, and step 2 restores 2000, so the timer starts over.
- Optional reset while the drive runs. Add the same SYS COUNTMAX = 0 action on the drive's running bit only if a running machine should keep the panel open.
| Event trigger | Action | Result |
|---|---|---|
| SYS BIT ON at power-up | SYS COUNTREPEAT = ON, SYS COUNTINTERVAL = 1000 | counter steps once per second |
| SYS COUNTVALUE = 0 | SYS COUNTMAX = 2000 | ceiling restored, count restarts |
| SYS COUNTVALUE > 1800 | write the lock screen number to the "switch to screen number" tag | panel moves to the password screen |
| covered button press, or drive running | SYS COUNTMAX = 0 | count rolls to zero, timer restarts |
Worked example: a 30-minute lockout
Target: lock after 30 minutes with no button press.
- 30 min x 60 s/min = 1800 s. At one count per second, the threshold is 1800 counts, written SYS COUNTVALUE > 1800.
- The comparison is strictly greater than, so the event fires at 1801 counts, about one second past the 30-minute mark.
- Ceiling check: 2000 counts at one per second is 33 min 20 s before the roll-over, and 1800 sits 200 counts below it, so the switch fires first. Keep the ceiling a few hundred counts above your threshold.
- Bench value: 120 counts = 120 s = 2 min. Commission with SYS COUNTVALUE > 120, then load 1800.
The build these numbers came from ran 1200 counts, a 20-minute lockout: 20 x 60 = 1200. Same math, different threshold.
What resets the timer, and what does not
Only the events you wire. Each pushbutton on your reset list restarts the count. Anything left off the list keeps the timer running: in the original build, typing a speed on a keypad or recalling a recipe tripped no reset, so the panel could lock while an operator was mid-entry. Test your entry screens the same way you test the buttons. If no entry action can trip a reset, keep the 30-minute timeout, which is long enough for an entry to finish, and accept the password prompt on return.
The drive-running reset is a policy choice. It holds the panel open for as long as the machine runs, including the hours it runs with nobody standing there, so use it only where a running machine must stay operable.
How to check it worked
- Put SYS COUNTVALUE on a test display and power the panel up. The value should step once per second and roll to zero at 2000.
- Press each covered button. The value should fall to zero and the ceiling should read 2000 again.
- With the 120-count threshold loaded, leave the panel alone. At about 2 minutes it should switch to the lock screen, and a touch must not bring the operating screen back.
- Enter the password and confirm control returns.
- Load the 1800 threshold and download the project.
Recommendation: for a 30-minute lockout, set SYS COUNTINTERVAL to 1000, SYS COUNTMAX to 2000 and the switch at SYS COUNTVALUE > 1800, and reset SYS COUNTMAX to 0 from every pushbutton operators use. Add the drive-running reset only when the machine must stay operable while it runs; skip it when the point of the lock is stopping walk-up control of the drive. Commission at a threshold of 120, confirm the password gate blocks machine actions, then load 1800.
Questions
Can I use the _1MIN_CLOCK system tag instead of the counter?
You can see it in the tag list, but it does not fit this job. A minute clock changes on its own schedule, so it tells you wall-clock time and never how long since the last touch. The event manager on these panels also has no increment action: actions set a tag to a constant or copy another tag, so there is no clean way to build a minute counter from it. The SYS COUNT tags are the counter the panel maintains for you, and a reset you control restarts them.
I want a 60-minute timeout. What changes?
Raise both numbers. Sixty minutes is 60 x 60 = 3600 seconds, so the switch condition becomes SYS COUNTVALUE > 3600. The 2000 ceiling rolls over at 33 minutes 20 seconds, long before that, so set SYS COUNTMAX to 4000 and write the same 4000 in the SYS COUNTVALUE = 0 restore event. Keep the ceiling a few hundred counts above the threshold and the counter never rolls before the lock fires.
What happens to the lockout after a power cut?
The panel comes back on the lock screen, because your lock screen is the startup screen, so the password gate stands before anything else. The SYS BIT ON event re-arms the counter at power-up and the count starts climbing again. Nobody returns to the operating screen they left before the cut.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.