Function Related To Start; Pre-Reading Start Function - Mitsubishi Electric MELSEC iQ-R-RD75P4 User Manual

7.6

Function Related to Start

As the functions related to start, Pre-reading start function and Start time adjustment function are provided. Each function is
executed by setting parameters or creating and writing a program.

Pre-reading start function

This function is provided to ensure the compatibility with the QD75N and LD75. Pre-reading start function does not output
pulses while Execution prohibition flag is on if a positioning start request is given with the Execution prohibition flag on, and
starts outputting pulses within 0.88ms after the off state of Execution prohibition flag is detected.
Control details
The pre-reading start function is performed by turning on Positioning start signal [Y10, Y11, Y12, Y13] or executing the
dedicated instruction (GP. PSTRT) while Execution prohibition flag [Y14, Y15, Y16, Y17] is on. If the positioning is started
while Execution prohibition flag is on, the positioning data is analyzed but pulses are not output. While Execution prohibition
flag is on, the setting of [Md.26] Axis operation status remains 5: Analyzing. When Execution prohibition flag [Y14, Y15, Y16,
Y17] is turned off, the RD75 starts outputting pulses within 0.88ms, and changes [Md.26] Axis operation status to the status
(such as Position control and In speed control) according to the control method used.
The pre-reading start function is invalid if Execution prohibition flag is turned off in the time between when Positioning start
signal is turned on and when the analysis of the positioning data is completed (Ta < Start time). (Ta is the time from when
Positioning start signal [Y10, Y11, Y12, Y13] is turned on to when Execution prohibition flag [Y14, Y15, Y16, Y17] is turned
off.)
V
Positioning start
ON
signal
[Y10, Y11, Y12, Y13]
Execution
prohibition flag OFF
[Y14, Y15, Y16, Y17]
ON
BUSY signal
[XC, XD, XE, XF]
Axis operation
Md.26 Position control
status
Control precautions
• The time required to analyze the positioning data is up to 7ms.
• After the positioning data analysis, the system is put in the execution prohibition flag OFF waiting state. Any change made
to the positioning data in the execution prohibition flag OFF waiting state is not reflected on the positioning data. Change
the positioning data before turning on Positioning start signal.
• The data numbers (set in [Cd.3] Positioning start No.) that can be used for the positioning start using the pre-reading start
function are from No.1 to 600. If any number between 7000 to 7004 or 9001 to 9004 is set and the pre-reading start function
is performed, Outside start No. range (Error code: 19A3H) occurs.
• Always turn on Execution prohibition flag at the same time or before turning on Positioning start signal. Pre-reading may not
be started if Execution prohibition flag is turned on after Positioning start signal is turned on and during Ta. The pre-reading
start function is invalid if Execution prohibition flag is turned on after the positioning start (pulse output) is performed while
Execution prohibition flag is off. (The function is enabled at the next positioning start.)
Start time
ON
OFF
ON
OFF
Positioning
data analysis
Standby
Positioning start timing
OFF
0.88ms or less
Ta
Execution prohibition
flag OFF waiting
Analyzing
ON
Position control
7 CONTROL SUB FUNCTIONS
7.6 Function Related to Start
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