Pre-Reading Start Function - Mitsubishi Electric MELSEC-Q Series User Manual

13.7.7 Pre-reading start function

V
Positioning start signal
[Y10 to Y1F]
Cd. 183 Execution
prohibition flag
BUSY signal
[X10 to X1F]
Md. 26 Axis operation
status
The "pre-reading start function" does not start servo while the execution prohibition flag
is ON if a positioning start request is given with the execution prohibition flag ON, and
starts servo within operation cycle after OFF of the execution prohibition flag is
detected. The positioning start request is given when the axis is in a standby status,
and the execution prohibition flag is turned OFF at the axis operating timing.
The "pre-reading start function" will be explained below.
[1] Controls
[2] Precautions during control
[3] Program examples
[1] Controls
The pre-reading start function is performed by turning ON the positioning start
signal with the execution prohibition flag ([Cd.183]) ON. However, if positioning is
started with the execution prohibition flag ON, the positioning data is analyzed
but servo start is not provided. While the execution prohibition flag is ON,
"[Md.26] Axis operation status" remains unchanged from "5: Analyzing". The
servo starts within operation cycle after the execution prohibition flag has turned
OFF, and "[Md.26] Axis operation status" changes to the status (e.g. position
control, speed control) that matches the control method. (Refer to Fig.13.48)
ON
OFF
ON
OFF
ON
OFF
Position control Standby
Fig. 13.48 Operations of pre-reading start function
Positioning start timing
Ta
Positioning data
Execution prohibition flag OFF waiting
analysis
Analyzing
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Chapter 13 Control Sub Functions
Operation cycle or less
t
Position control