How can I ignore the AT CURRENT LIMIT flag when increasing load on a machine tool?
This allows the AT CURRENT LIMIT flag to be ignored during acceleration and deceleration. Useful for machine tools which need to know about increased load when a tool wears, but don’t want nuisance trips when changing speed.
It does so by using the INTERVAL TIMER to hold off the flag for a short period - enough for the drive to finish accelerating or decelerating. The result of this is of course that there will be a delay before the flag operates when there is a genuine current limit event, but this is unavoidable. The instructions assume that you want to use DOP2 for the output.
Go to CONFIGURATION, ENABLE GOTO,GETFROM and set to ENABLED.
Go to APPLICATION BLOCKS, MULTI-FUNCTION 1, 544)MULTIFUN1 MODE and set it to INVERT
Go to APPLICATION BLOCKS, MULTI-FUNCTION 1, 545)MULTIFUN1 OP SEL and set it to ENABLED
Go to APPLICATION BLOCKS, MULTI-FUNCTION 1 and set its GET FROM to 141)AT CURRENT LIMIT
Go to APPLICATION BLOCKS, MULTI-FUNCTION 1 and set its GOTO to 584)TIMER RESET
Go to CONFIGURATION, DIGITAL OUTPUTS, DOP2 T23) SETUP and set its GET FROM to 586)TMR EXPIRED FLAG
Go to CONFIGURATION, BLOCK OP CONFIG, INTERVAL TIMER GOTO and set it to 300)ANALOG POST 1 (it doesn't matter where you take this - any unused PIN will do - it just activates the block).
Go to CONFIGURATION, ENABLE GOTO,GETFROM and set to DISABLED. Finally, go to APPLICATION BLOCKS, INTERVAL TIMER, 585)TIMER INTERVAL and set it to something a little longer than the natural acceleration/deceleration time.
If you find DOP2 works the wrong way around for your system, i.e. high when it should be low and vice versa, go to CONFIGURATION, DIGITAL OUTPUTS, DOP2 T23) SETUP, 266)DOP2 INVERT MODE and set it to INVERT.
Once you are happy, don't forget to do a PARAMETER SAVE.