p command

[kandauru]

What is laying behind p command?

I am trying to get a position, but it is different if I run online command - #1p and look at motor[1].ActPos or motor[1].Pos values.

Thank you in advance.

[Jay Lee]

Please refer to Power PMAC Software Reference Manual, for online command, p

Motor[x].ActPos is the position after power-on.

p command will take out home position out of Motor[x].ActPos.

So if you have any home offset, then they will be different.

 

Here is a portion of the content for p command for motor

//======================

 

If Motor[x].PosReportMode (new in V1.6 firmware, released 3rd quarter 2013) is set to its default value of 0, or in an older firmware version that does not have this new element, the values in these offset-mode registers are subtracted from the net desired position. Working from the source registers for Motor[x], the reported position is calculated as:

 

+ Pos // Raw feedback position relative to power-on/reset location

+ CompPos // Compensation table measurement correction

+ PresBlSize // Backlash correction

- CompDesPos // Compensation table command offset

- ActiveMasterPos * MasterCtrlOffsetBit // Master position when in offset mode

- HomePos // Motor zero position relative to power-on/reset location

 

If Motor[x].PosReportMode is set to 1, the values in these offset-mode registers are not subtracted from the net desired position. In this case, the reported position is calculated as:

 

+ Pos // Raw feedback position relative to power-on/reset location

+ CompPos // Compensation table measurement correction

+ PresBlSize // Backlash correction

- HomePos // Motor zero position relative to power-on/reset location

 

//=========

[kandauru]

Thank you very much!