Difference between revisions of "How to setup Position Error Delay"

From SoftMC-Wiki
Jump to: navigation, search
(example file)
Line 4: Line 4:
  
 
* set [[MC-Basic:axis.POSITIONERRORDELAY|PEDEL]] to 1 (minimum value)
 
* set [[MC-Basic:axis.POSITIONERRORDELAY|PEDEL]] to 1 (minimum value)
 +
* set high value in PeMax
 
* Run the axis back and forth and record PE and VCMD as :
 
* Run the axis back and forth and record PE and VCMD as :
  
Line 44: Line 45:
 
So setting [[MC-Basic:axis.POSITIONERRORDELAY|PEDEL]] to 5.078 we get:<br>
 
So setting [[MC-Basic:axis.POSITIONERRORDELAY|PEDEL]] to 5.078 we get:<br>
 
[[Image:PE_PEDEL5078.PNG|800px]]<br>
 
[[Image:PE_PEDEL5078.PNG|800px]]<br>
 +
 +
 +
== Example File ==
 +
 +
 +
'''PDLtune.prg'''
 +
<syntaxhighlight lang="vb">
 +
 +
'
 +
common shared Ax as generic Axis
 +
 +
program
 +
 +
dim i as long
 +
 +
Ax = A1
 +
with Ax
 +
Attach
 +
Pedel = 1 ' first run
 +
Pedel = 1 + round(1.68 / 100.0 * 1000.0 / (bus[0].cycleTime/1000)) ' 2nd run. extracted from recordings
 +
Pedel = Pedel + 0.075 / 100.0 * 1000.0 / (bus[0].cycleTime/1000) ' 3rd run. extracted from recordings
 +
PeMax = 10
 +
En=1
 +
Sleep 100
 +
Move 0 Vcruise=100 Abs=TRUE
 +
call waitMotion
 +
Record ax_PE.rec 100000 Gap=1 RecData = Ax.Pe, Ax.Vcmd
 +
RecordOn
 +
Sleep 100
 +
for i = 1 to 3
 +
Move 100 Vcruise=100 Abs=TRUE
 +
call waitMotion
 +
Sleep 100
 +
Move 0 Vcruise=100 Abs=TRUE
 +
call waitMotion
 +
Sleep 100
 +
next
 +
RecordClose
 +
En=FALSE
 +
Sleep 100
 +
PeMax = 0.1
 +
Detach
 +
end with
 +
 +
terminate program
 +
 +
 +
sub waitMotion
 +
while Ax.IsMoving
 +
Sleep 1
 +
end while
 +
end sub
 +
 +
</syntaxhighlight>

Revision as of 16:40, 31 May 2015

How to SetUp Position Error Delay

First Step

  • set PEDEL to 1 (minimum value)
  • set high value in PeMax
  • Run the axis back and forth and record PE and VCMD as :

PE VCMD.PNG
Command Velocity recordings


PE PEDEL1.PNG
Position Error recordings


Compute PEDEL as PE/VCMD, in this case it will be: 

PE/VCMD = 0.94/57.74*1000 = 16.2 ms

Taking into account the used value of PEDEL (1) and the sampling time of 4ms we get the new PEDEL value of 5, e.i. PEDEL = 1 + 4 = 5

Second Step

Change the PEDEL(5) to the integer value estimated before and run the test again:

PE PEDEL5.PNG

again estimate the error: 

PE/VCMD = 0.18/57.74*1000 = 0.317 ms
IMPORTANT.svgIMPORTANT
This means the non-integer communication delay of the drive is 317 micro-seconds.




which is in units of one sample equal: 

317/4000 = 0.078


So setting PEDEL to 5.078 we get:
PE PEDEL5078.PNG


Example File

PDLtune.prg 

'
common shared Ax as generic Axis

program
	
	dim i as long

	Ax = A1
	with Ax
		Attach	
			Pedel = 1 ' first run
			Pedel = 1 + round(1.68 / 100.0 * 1000.0 / (bus[0].cycleTime/1000)) ' 2nd run. extracted from recordings
			Pedel = Pedel + 0.075 / 100.0 * 1000.0 / (bus[0].cycleTime/1000) ' 3rd run. extracted from recordings
			PeMax = 10
			En=1
			Sleep 100
			Move 0 Vcruise=100 Abs=TRUE
			call waitMotion
			Record ax_PE.rec 100000 Gap=1 RecData = Ax.Pe, Ax.Vcmd
			RecordOn
				Sleep 100
				for i = 1 to 3
					Move 100 Vcruise=100 Abs=TRUE
					call waitMotion
					Sleep 100
					Move 0 Vcruise=100 Abs=TRUE
					call waitMotion
					Sleep 100
				next
			RecordClose		
			En=FALSE
			Sleep 100
			PeMax = 0.1
		Detach
	end with
	
terminate program


sub waitMotion
	while Ax.IsMoving
		Sleep 1
	end while
end sub
Retrieved from "http://softmc.servotronix.com/index.php?title=How_to_setup_Position_Error_Delay&oldid=125502"