How Fast is My Servo Axis Moving?

An Axis Parameter has been added to display the Encoder velocity in 'RPM'. This register will display the encoder RPM updated each Period. If RPM factor > 0 then the algorithm turns on to calculate the RPM. This RPM will be determined by the RPM factor for each axis using the following formula.

RPM Factor = 60 / ((Encoder pulse count per unit) * Servo Period)

Encoder pulse count = (Encoder pulses per revolution * encoder multiplier * encoder revolutions per unit)
{Typically the PPU of the Axis}

	AXIS0	AXIS1	AXIS2	AXIS3	AXIS4	AXIS5	AXIS6	AXIS7
RPM Factor	P12370	P12626	P12882	P12128	P13394	P13650	P13906	P14162
Actual RPM	P12371	P12627	P12883	P12129	P13395	P13651	P13907	P14163

	AXIS8	AXIS9	AXIS10	AXIS11	AXIS12	AXIS13	AXIS14	AXIS15
RPM Factor	P14418	P14674	P14930	P15186	P15442	P15698	P15954	P16210
Actual RPM	P14419	P14675	P14931	P15187	P15443	P15699	P15955	P16211

Usage example:
The motor encoder has a 500 PPR, the ACR card has the multiplier set to MULT 4 and the axis has 2.5 encoder revolutions per inch of travel.

REM Encoder pulse count = (500 * 4 * 2.5) = 5000
REM Default PERIOD = 0.0005
REM RPM Factor = 60 /(5000 *0.0005) = 24
REM P12370 = 24

100 P12370 = 60 /(5000 *0.0005)
120 PRINT "Encoder RPM = ";P12371

Sample program to display average RPM
ATTACH MASTER0
ATTACH SLAVE0 AXIS0 "X"

MULT X4
PPU X5000
ACC 100
DEC 100
STP 100
F 100

REM Set value of RPM factor
P12370 = 60 /(5000 * 0.0005)

10 RES X
REM Set random Feedrate (5-100)
20 LV2 = ((RND 90)+5)
30 F (LV2)
REM Set random distance (5-30)
40 LV3 = ((RND 25)+5)
50 X (LV3)
60 DV0=0 : LV1=1
70 INH 516
80 PRINT" Feedrate = "; LV2;" Distance = ";LV3

REM Add RPM samples to average
200 DV0 = (DV0 + P12371)
REM Count number of samples
220 LV1 = (LV1+1)
REM Loop if axis still moving
240 IF (BIT 516) THEN GOTO 200
260 DWL 0.1
300 PRINT " Number of samples = ";LV1
320 PRINT USING "##.##";" Average RPM = ";(DV0/LV1)
340 PRINT " "
360 DWL 5
380 GOTO 10
400 END

DIM LV5
DIM DV1