
4. REFERENCE POSITION ESTABLISHMENT
B--63003EN--1/02
400
[Example parameter setting]
When the following scale is used with an IS--B, millimeter machine
Scale origin
Mark1=Mark2 Mark1 Mark2
20.000
19.980
0.020
9.940 10.060
9.960
10.040 9.980 10.020
5.000
20.000mm
20.020mm-- [9960/(20020--20000)*20000+5000] = --9965000
Mark1 Mark1 Mark2 Mark1 Mark2 Mark1 Mark1Mark2
Positive
direction
Reference position
Negative
direction
AB
Parameter No. 1821 (mark 1 interval) = “20000”
No. 1882 (mark 2 interval) = “20020”
No. 1883 (reference position) = Position of point A +5.000
Distance between A and B
Mark 2 interval -- Mark 1 interval
9960
20020--20000
= 9965000
→ “--9965000”(reference position in the negative direction)
= * Mark 1 interval+5.000
= * 20000+5000
[Method of setting parameter No. 1883]
If it is difficult to measure the distance between the scale origin and
reference position (parameter No. 1883), the parameter can be set as
follows:
(1)Set parameter No. 1815 to enable this function.
Set parameters No. 1821 and 1882 appropriately.
Set parameter No. 1240 to 0.
Set parameter No. 1883 to 0.
(2)At an appropriate position, establish the reference position as
described in ”Basic procedure for establishing the reference position”
(as a result, the machine coordinate becomes the distance between the
scale origin and current position).
(3)Position the machine to the reference position, by jog feed or handle
feed.
(4)Convert the current machine coordinate (displayed with No. 301 on the
diagnosis screen) to a value in detection units (by multiplying the
value of No. 301 by CMR), then set the result for parameter No. 1883.
(5)If necessary, set parameter No. 1240.