Chapter 13 Programming; Precautions On Programming - Mitsubishi Electric MELSEC iQ-R-RD75P4 User Manual

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PROGRAMMING
This chapter describes the program required for performing the positioning control with the RD75. When creating a program
required for the control, consider Start condition, Start time chart, Device setting, and the configuration of the whole control.
(According to the control to be performed, set data such as parameters, positioning data, block start data, and condition data
for the RD75, and create a setting program of control data and a start program of each control.)
13.1

Precautions on Programming

This section describes common precautions for writing data of the CPU module to the buffer memory of the RD75.
Reading/writing data
Using an engineering tool is recommended to set the data shown in this chapter (various parameters, positioning data, and
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block start data). Because setting the data with programs requires many programs and devices, the execution becomes
complicated, and the scan times will increase. When changing positioning data during the continuous path control or
continuous positioning control, rewrite the data before positioning data four steps before is executed. If data has not been
rewritten when positioning data four steps before is executed, the data is processed as data that is not rewritten.
Restrictions on the execution interval of speed change
To change the speed successively using the speed change function or override function in the RD75, set 10ms or longer as
the interval between each speed change.
Measures against an overrun
Setting [Pr.12] Software stroke limit upper limit value and [Pr.13] Software stroke limit lower limit value of detailed parameter 1
can prevent an overrun. Note that this is valid only when the RD75 is operating normally. Set limit switches to ensure the
safety of the entire system. Establishing an external circuit through which the motor power turns off when a limit switch turns
on is recommended.
13 PROGRAMMING
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13.1 Precautions on Programming