11 - 18 
MELSEC-Q
 
11   MANUAL CONTROL 
 
 Precautions during operation 
 
The following details must be understood before inching operation is carried out. 
(1) Acceleration/deceleration processing is not carried out during inching 
operation. 
(Pulses corresponding to the designated inching movement amount are output 
at the first control cycle of the QD75 (3.5 ms). The movement direction of 
inching operation is reversed and, when a backlash compensation is carried 
out, first pulses corresponding to the backlash amount are output in the first 
control cycle of the QD75 and then pulses corresponding to the designated 
inching movement amount are output in the subsequent control cycles.) 
The "
Cd.17
JOG speed" is ignored even if it is set. An error will occur in the 
following cases (error code: 301). 
(
Cd.16
Inching movement amount) x (A) > (
Pr.31
JOG speed limit value) 
Where (A) is as follows. 
• When the unit is PLS:  562.5 
• When the unit is other than PLS: 337.5 
 
(2) JOG start signal OFF 
 ON immediately after stop signal ON   OFF (within 
100 ms) is ignored. 
(Operation will not start.) 
 
(3) Set a value other than a "0" in "
Cd.16
Inching movement amount". 
If a "0" is set, the operation will become JOG operation (Refer to section 11.2 
"JOG operation". 
 
 Errors during operation 
 
If the operation is stopped by the stroke limit (limit switch OFF), inching operation 
can be carried out in the direction in which the limit switch turns ON.  
(JOG start signals in the direction in which the limit switch turns OFF will be 
ignored.) 
 
Inching operation possible
Upper/lower limit switch
Inching operation
V
Inching operation not possible