Mitsubishi Electronics QD75D, QD75P 9.2.6 1-axis fixed-feed control

9 - 43
MELSEC-Q
9 MAJOR POSITIONING CONTROL
9.2.6 1-axis fixed-feed control
In "1-axis fixed-feed control" ("Da.2 Control s ystem" = fixed-feed 1), one motor is
used to carry out fixed-feed control in a set axis direction.
In fixed-feed control, any remainder of the m ovement amount designated in the
positioning data is rounded down if less t han that required for control accuracy to
output the same amount of pulses. (The remaind er of the movement amount with an
accuracy below the control accuracy does no t affect the regular controls.)
Operation chart
In 1-axis fixed-feed control, the address ( Md.20 Current feed value) of the current
stop position (start point address) is set to "0". Positioning is then carried out to a
position at the end of the movement amount set in " Da.6 Positioning
address/movement amount".
The movement direction is determined by the movement amount sign.
00000
" Md. 20 Current feed
value" is set to "0" at
the positioning start
Designated movement
Positioning
start amount
Reverse direction Forward direction
Stop position
Movement direction for
a negative movement amount
Movement direction for
a positive movement amount
Restrictions
(1) An axis error "Continuous path control not possib le (error code: 516)" will
occur and the operation cannot start if "continuous path control" is set in
"Da.1 Operation pattern". ("Continuous path control" cannot be set in fixed-
feed control.)
(2) "Fixed-feed" cannot be set in " Da.2 Control system" in the positioning dat a
when "continuous path control" has been set in " Da.1 Operation pattern" of
the immediately prior positioning data. (For example, if the operat ion pattern of
positioning data No. 1 is "continuous path control", fixed-feed cont rol cannot
be set in positioning data No. 2.) An axis error "Continuous path c ontrol not
possible (error code: 516)" will occur and the machine will carry out a
deceleration stop if this type of setting is carried out.