Problem with the loop of autostart.pc

    • New

    Hi everyone, i'm trying to do a structure of autostarts where autostart5.pc is the main pc program that gets activated when the robot turns on, autostart5.pc checks if autostart2.pc is on, if not it turns it on. (pc2 does the same with the 3rd)

    In all others autostart i check if autostart5.pc is on if not i turn it on.

    This way if an autostart is aborted it gets immediately executed by another and you can oly stop them all togheter.

    I'd like to use these autostart to check alarms and errors.

    The problem is they stops and wait when they reach the line "TWAIT 0.1" (i use this timer for the load on the CPU).

    i'll leave you the images with the code and the terminal with the statuses of the pc programs.

    Any tips would be helpful


    (p.s.)

    i tried to insert a print to see if it was looping but it doesn't print

  • Go to Best Answer
    • New
    • Best Answer

    PC Tasks and managing them is not the easiest thing to achieve and can be a very frustrating journey..........:censored:

    PRINT commands fall into this category as PRINT requires a device to send it to as that is it's purpose really, not locally.
    Check out the PRINT command in the AS manual for further information on this.

    If you locally PCEXE the PC Task, then you can get it to print locally.
    If you are connected to a live controller, then I think from memory, you need to set PRINT as PRINT 3:

    Only advice I can give is avoid the PRINT.
    Instead set a string window on the IFP of the teach pendant and use IFPWPRINT but only use IFPWPRINT when a change occurs and not constantly as it can hog resources.

    Regarding the management of PC Tasks, many ways can be done but fundamentally you always need the master running in order to monitor and restart other tasks, so it is better to just have that master doing that and nothing else - similar to what you've posted above.

    I use a very different method that allows PC2 to start up on initial start of PC1 if it's not running after 1 sec has elapsed.
    Then if PC2 turns off, it restarts and also I can independently turn off PC2 to debug it without PC1 firing it back up again.

    Have a play with it and see if you can use it.

    • New
    Quote from Giacomo Pellegrini

    Yes i'm sorry... my head is all over the place

    Lol.......We've all been there.
    I myself am a regular customer of Mrs face palmer, she's knows me very well indeed.

    Attached is the video of it in action using 3 PC Tasks, one as the 'master' waking the others up, restarting them if they stop, stopping them all and clearing them down from the stack but not restarting them if I am wanting to debug them instead.

    I like this method as it gives plenty of scope and works and you can just have 1 task like wdog.pc in my demo JUST doing that monitoring and control, therefore it will never stop or fail.

    PCTask Management.mp4

    • New

    Instead of trying to use TWAIT in your autostarts, have a look at PCSCAN to reduce the CPU load.



    Having said that I take a completely different approach to Autostarts.

    I always leave slot 1 open so it's easy to run any stand along programs manually without having to specify which slot it needs to run in.

    I have a watchdog timer that Prints out a message if any of the autostarts takes longer than a certain threshold to execute a single scan so that you can easily see if something in your code starts hogging all the CPU time or if anything falls into and infinite loop.

    Be careful with prints as they holdup program execution until the message is printed. You can see this easily if you make a motion loop and add a bunch of print statements everywhere and monitor the cycle time. Then comment out all the prints and check the cycle time again.

    Generally in PC programs the loop continuously never use TWAIT or PRINTS or anything that will hold up the code execution within the loop.

    Autostart 2 Is used for TCP/IP comms. Medium priority

    Autostart 3 Is for data mapping to/from PLC and Faults . Medium priority like 100ms

    Autostart 4 has very little code and on the highest priority 40ms for storing accurate locations on and interrupt from the motion code.

    Autostart 5 is super low priority like second and used for Logging errors, rates etc.

Advertising from our partners