Turbo PMAC Command buffer overflow

[Abhijit]

Through PLC program, I want to use following construction:

 

If (I5111 !> 0)

CMD"#1j=* #3j=*"

I5111=100*8388607/I10

EndIf

 

Above program will issue jog command every 100 milli seconds.

 

My query is: How fast can I issue jog command like above ensuring that Turbo PMAC command buffer will not overflow ?

[Richard Naddaf]

I am not sure what the application requires but short answer is: As fast as the PLC is executing, and amount of queued commands in the buffer. Every time you change the variable target and J=* is issued the motor will try to go to the new target position.

 

Ultimately, you would have to do some testing to make sure it is good enough for your application.

 

Otherwise, I usually recommend doing this in a motion program using for example X(P1000) around an endless while loop, small TA and TS and some Feedrate F. Where P1000 is being updated at a certain frequency. We use this method successfully in Telescopes tracking star trajectories.

[Abhijit]

Do you use "LINEAR" for this ? What values do you use for F, TA & TS ? Could you please provide a sample code ?

[steve.milici]

Note that you should be able to send the "J=*" command at a period equal to or greater than the jog acceleration time, Ixx20/Ixx21.

 

As far as the F, TA and TS settings, these should be set as required by your application needs.