Mitsubishi Q2ACPU User Manual page 181

10. OTHER FUNCTIONS
(d) Constant scan time error
If there is a low-speed execution type program when performing the constant
scan, the constant scan time may be shifted by the time shown below.
Maximum processing time
of one instruction in the
(Error)
=
low-speed execution type
program
The low-speed execution type program is divided and performed within surplus
time. Therefore, if one constant scan ends while performing the instruction takes
long processing time, the constant scan is completed after finishing the
processing of the instruction during execution. The time extended to complete
the execution of the instruction is the constant scan error. For details of the
instruction processing time, refer to the QCPU (Q mode)/QnACPU Programming
Manual (Common Instructions).
+ low-speed END processing time
Time taken to execute the END
processing for a low-speed
execution type program
10 - 4