Mitsubishi Electric MELSEC iQ-R Series User Manual page 30

Units used in control
Units of the position, speed, acceleration/deceleration, and jerk that are used in the motion system follow the technical units of
the axis to be used. For details, refer to the following.
Page 62 Technical Units
The following types exist in the control value such as the position and the speed that are used in the motion system. For
details of the control value related to the position and the speed, refer to the following.
Page 67 Positioning Range, Page 70 Velocity Range
Name
Commanded value
Set value
Actual value
MCFB input/output specifications
The common specifications of MCFB I/O variables are described in this section.
■I/O variable/input variable/output variable
For details, refer to specifications of each FB.
■Omission of input variable
When omitting to input FBs, the default value that is defined for each FB is applied. For details of the default value, refer to
specifications of each MCFB.
When omitting to input the speed, etc. in the multiple start FB, the input value of the previous FB is taken over. For details,
refer to the following.
Page 107 Multiple Start (Buffer Mode)
■Refresh timing of input/output
Each argument of the FB is refreshed at a call timing of the FB. To control the input/output of the FB synchronizing with the
operation cycle, call the FB from a fixed cycle program whose cycle is the same as the operation cycle.
■Specification of I/O No.
When using the MCFB in the CPU module side, needs to specify the I/O No. of the target Motion module to the I/O variables
(ex. AxisName.AxisRef.IO_No) that are used in the MCFB. For details, refer to the following.
Page 491 HOW TO CONTROL FROM CPU MODULE
When using the MCFB in the motion system, the I/O No. needs not to be specified. (The specification is ignored.)
Precautions
• I/O arguments of the MCFB are refreshed at a call timing of the FB, but the cycle that the control is actually executed differs
depending on the FB. For example, the motion FB performs the control at the operation cycle regardless of the FB call task
(normal/fixed cycle). For details, refer to specifications of each FB.
• The FB imports input values when turning TRUE the execution command (Execute and Enable). Therefore, set input
values before turning TRUE the execution command (Execute and Enable).
• After turning TRUE the execution command (Execute) of the positioning control FB, in order to turn FALSE the execution
command (Execute), turn it FALSE after the executing (Busy) turned into the TRUE status.
Program examples
For details, refer to specifications of each FB.
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Meaning
A value based on an input to the MCFB (the target value). Commanded position and commanded speed, etc.
The curent control value that is generated by motion operation. Set position and set velocity, etc.
A value obtained by converting the actual value from the slave device on the real axis into the technical units of the
axis. Actual position and actual speed, etc.