Mitsubishi Electric MR-J2S-A Instruction Manual page 150

5. PARAMETERS
(b) Conveyor setting example
For rotation in increments of 0.01 per pulse
Machine specifications
Table : 360 /rev
Reduction ratio: n
Servo motor resolution: Pt
CMX Pt
0.01
CDV
Since CMX is not within the setting range in this status, it must be reduced to the lowest term.
When CMX has been reduced to a value within the setting range, round off the value to the
nearest unit.
CMX 65536 26214.4
CDV 1125
Hence, set 26214 to CMX and 450 to CDV.
(2) Instructions for reduction
The calculated value before reduction must be as near as possible to the calculated value after
reduction.
In the case of (1) (b) in this section, an error will be smaller if reduction is made to provide no fraction
for CDV. The fraction of Expression (5.1) before reduction is calculated as follows.
CMX 65536
58.25422 .................................................................................................................... (5.2)
1125
CDV
The result of reduction to provide no fraction for CMX is as follows.
CMX 65536 32768
CDV 1125 562.5
The result of reduction to provide no fraction for CDV is as follows.
CMX 65536 26214.4
CDV 1125 450
As a result, it is understood that the value nearer to the calculation result of Expression (5.2) is the
result of Expression (5.4). Accordingly, the set values of (1) (b) in this section are CMX 26214,
CDV 450.
4/64
131072 [pulses/rev]
131072 65536
................................................................................. (5.1)
4/64 360 1125
26214
450 450
POINT
When "0" is set to parameter No.3 (CMX), CMX is automatically set to the
servo motor resolution. Therefore, in the case of Expression (5.2), setting
0 to CMX and 2250 to CDX concludes in the following expression:
CMX/CDV=131072/2250, and electric gear can be set without the
necessity to reduce the fraction to the lowest term.
For unlimited one-way rotation, e.g. an index table, indexing positions will
be missed due to cumulative error produced by rounding off.
For example, entering a command of 36000 pulses in the above example
causes the table to rotate only the following:
26214 1
36000
450 131072
Therefore, indexing cannot be done in the same position on the table.
32768
58.20249 .................................................................................... (5.3)
563
26214
58.25333 .................................................................................. (5.4)
450
5 - 27
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Servo motor
131072 [pulse/rev]
Timing belt : 4/64
4
360 359.995
64
Table