Mitsubishi Electric MELSERVO-J4 series, Instruction Manual

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17 APPLICATION OF FUNCTIONS
17.1 Scale measurement function
535
17
17
APPLICATION OF FUNCTIONS
This chapter explains application of using servo amplifier functions.
17.1
Scale measurement function
The scale measurement function transmits position information of a scale measurement encoder to the controller by
connecting the scale measurement encoder in semi closed loop control.
The scale measurement function is available for servo amplifiers with software version A1 or later.
When a linear encoder is used as a scale measurement encoder for this servo amplifier, "Linear Encoder
Instruction Manual" is necessary.
When the scale measurement function is used for MR-J4-_GF_ servo amplifiers, the following restrictions
apply. However, these restrictions will not be applied to MR-J4-_GF_-RJ servo amplifiers.
• A/B/Z-phase differential output type encoder cannot be used.
• The scale measurement encoder and servo motor encoder are compatible with only the two-wire type. The
four-wire type scale measurement encoder and servo motor encoder cannot be used.
• When you use the HG-KR and HG-MR series for driving and scale measurement encoder, the optional four-
wire type encoder cables (MR-EKCBL30M-L, MR-EKCBL30M-H, MR-EKCBL40M-H, and MR-EKCBL50M-
H) cannot be used. When an encoder cable of 30 m to 50 m is needed, fabricate a two-wire type encoder
cable according to the following section.

Page 606 Two-wire type encoder cable for HG-MR/HG-KR
The scale measurement function compatible servo amplifier can be used with any of the following controllers.
• Simple motion module RD77GF_/QD77GF_
For settings and restrictions of controllers compatible with the scale measurement function, refer to the
following and user's manuals for each controller.

Page 543 Controller setting of the scale measurement function
Functions and configuration
Function block diagram
The following shows a block diagram of the scale measurement function. The control will be performed per servo motor
encoder unit for the scale measurement function.
Servo motor feedback pulses
(Servo motor resolution unit)
Servo motor
Scale measurement encoder
S
Encoder pulse setting
([Pr. PA15], [Pr. PA16]
and [Pr. PC03])
+
-
+
-
+
-
Control
Monitor
Load-side feedback pulses
(Scale resolution unit)
Motor-side droop
pulses
Current position
(absolute position)
Scale within-1-rev
position
Scale ABS counter
Controller
Position command