Mitsubishi Electric MELSEC Q Series User Manual page 176

10 FUNCTION DETAILS
d) Subtract the result of expression a) above from that of c) and b)
respectively, and then compare the results as shown below.
| b) - a) | = | 157.2800 - 157.2864 | = 0.0064
| c) - a) | = | 157.5384 - 157.2864 | = 0.2520
From the above comparison, it is easy to see that the calculation
result of b) is closer to the value of a).
3) The value of the electronic gear has setting range and integer
restrictions. Therefore, round down the calculated value of the
numerator (AP) from expression (2) to the nearest integer and set it as
follows.
AP = 19660, AL = 125
(Note): Due to rounding down the numerator, this setting will result in a
differenve in value between the machine's actual position and
the position calculated by the controller.
This example's calculation error.
125
⎛
19660
⎜
625
⎝
(3 × 32768)
This mwans that for every 1km of movement, there is 40.7[mm]
of error. The error at the home position is 0.
Also, in an absolute position system, error does not accumulate
even if power is removed at the 1km mark mentiond in this
example.
10 - 5
⎞
⎟
- 1 × 100 = 4.07 × 10
⎠
MELSEC-Q
-3
[%]