Mitsubishi Electric MELSEC Q Series User Manual page 21

1 OVERVIEW
(c) OPR control is given additional features (Refer to Chapter 7.)
Six different OPR methods are provided: the proximity dog type, data set
type, stopper type, dog cradle type, limit switch combined type, and the
scale origin signal detection type.
(d) Two acceleration/deceleration control methods are provided: Liner
acceleration/deceleration and S-curve acceleration/deceleration.
(Refer to Section 10.7.)
(4) Quick startup
A positioning operation starts up quickly taking as little as 0.88[ms].
(5) SSCNET makes the connection to the servo amplifier possible
(a) The QD74MH can be directly connected to the Mitsubishi servo amplifier
MR-J3-B using the SSCNET .
(b) Because the SSCNET cable is used to connect the QD74MH and the
servo amplifier, or servo amplifiers, saving wiring can be realized. The
maximum distance between the QD74MH and servo amplifier, servo
amplifier and servo amplifier of the SSCNET cable on the same bus was
set to 50(164.04[m(ft.)], and the flexibility improved at the system design.
(c) The servo parameters can be set on the QD74MH side to write or read
them to/from the servo amplifier using the SSCNET .
(d) The actual current value and error description contained in the servo can be
checked by the buffer memory of the QD74MH.
(e) Wiring is reduced by issuing the external signal (upper/lower stroke limit
signal, proximity dog signal) via the servo amplifier.
(6) Easy application to the absolute position system
(a) The absolute position-corresponding servo motor and servo amplifier are
used to have an application to the absolute position system.
(b) Once the OP have been established, the OPR operation is unnecessary
when the power is supplied.
(c) With the absolute position system, the data set method OPR is used to
establish the OP.
(7) Easy maintenance
Each QD74MH positioning module incorporates the following improvements in
maintainability:
(a) Data such as the positioning data and parameters can be stored on a flash
ROM inside the QD74MH, eliminating the need of a battery for retaining
data. (Refer to Section 6.1.)
(b) Error messages are classified in more detail to facilitate the initial
troubleshooting procedure. (Refer to Section 11.1.)
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