YASKAWA G7 Technical Manual page 2

This document is intended to provide proper installation and use of the Yaskawa drive with custom software. This
document is a supplement to the standard drive technical manual. It describes the effects on the drive parameters
and functions with the software installed. Read and understand this document and the standard drive technical
manuals before attempting to install, adjust, operate, inspect, or maintain the drive. Observe all cautions and
warnings in this document and the standard drive technical manuals. Custom software is written to add
functionality to a standard AC drive to enhance or enable use in a specific application. The software is loaded to
the flash ROM area of the control board, and replaces the standard drive software. Custom software can add new
functions, modify standard functions, or even inhibit standard functions. It can be used to modify display text or
parameter names. Custom software is usually loaded to the drive before delivery. The control board and drive
nameplate are assigned unique part numbers and the software is registered, archived, and retrievable.
When seeking support for a drive with custom software, it is imperative to provide the unique part number shown
on the drive nameplate. The software has been flashed to the control board memory and the operation of
parameters, functions, and monitors are different than the standard drive software, as described herein.
1.0 Overview
The Electronic Lineshaft (ELS) function allows a drive to precisely follow a master encoder (PG) signal in
speed, direction, and phase. The follower can match its position (phase angle) to the master within several
quadrature encoder counts. The function is used in applications where the machinery being driven requires
two mechanically isolated, moving parts to maintain a constant position relationship. The gear ratio between
the master and the follower is infinitely adjustable. In addition, a gear ratio adjustment ("draw") can be added
to the speed reference via parameter, analog input, multi-function input, MOP, or network communication.
The drive can also be run in a pure speed follower mode for applications that do not require matched position,
only velocity following.
Both the master and follower encoder signals are fed into the follower drive's dual encoder (PG) option card.
The master encoder speed is multiplied by the programmed gear ratio to determine the speed reference. The
error between the master and follower position is determined. This is fed into a PI controller, which is in turn
added to the previously calculated speed reference. When the drive is configured as a speed follower, the
position regulator is disabled.
A signed-run mode is also available in ELS. When P1-01 = 5 (Electronic Line Shaft - Sign Run), ELS
functions identically to standard ELS (P1-01 = 4), with the following difference:
•
When a reverse run command is given through the terminal S2 digital input, the follower will match the
velocity and phase of the master, but in the opposite direction. If the master runs in the forward direction,
the follower will run in reverse direction. If the master runs in the reverse direction, the follower will run in
the forward direction.
•
When a forward run command is present through terminal S1, the follower will run in the same direction is
the master.
The Alignment function allows the follower drive to maintain a phase angle with respect to 2 alignment inputs
(can be sensors or encoder marker pulses). The phase angle, quantified as the Displacement in follower
encoder counts, can be adjusted during run either through keypad, digital multi-function inputs, or network
communication. The phase angle is maintained by monitoring alignment inputs (pulses) from both the master
alignment input and follower alignment input and then measuring the follower encoder counts received
between the two alignment pulses.
The Alignment function is enabled through the Align by Pulse multi-function digital input. When enabled, the
drive will monitor the Z (marker) channel inputs on any of the dual channel encoder option cards.
Please note that the alignment inputs need not come directly from encoder marker pulse channels. However,
special external circuitry may be required to support other input types, such as proximity sensors. Also, the
inputs do not have to be of the same type. Refer to Section 3.0 (Limitations) for application details.
Figures 1 ~ 3 below give overview to the Electronic Lineshaft and Alignment functions.
Date: 03/31/09, Rev: 09-03 Page 2 of 30 TM.G7SW.064