Mitsubishi Q00JCPU User Manual page 309

6
FUNCTIONS
(5) Constant scan accuracy
Basic Redundant Universal
UD
Note6.4 Note6.4 Note6.4
Basic
Note6.4
Note3
Basic Since the Basic model QCPU cannot use low speed execution type programs and fixed scan
Redundant Universal
UD
execution type programs, it is not necessary to be conscious of this description.
Note6.4 Note6.4
Note6.4
Since the Redundant CPU, Universal model QCPU cannot use low speed execution type
programs, it is not necessary to be conscious of this description.
Refer to Section 11.2 for the constant scan accuracy.
However, when the program indicated in (a) or (b) below is being executed, the
constant scan may be delayed.
(a) When low speed execution type program is executed
There is a waiting time of 0.5ms when a low speed execution type program is
being executed. (
• When maximum processing time of one instruction is within 0.5ms
The constant scan error is the same as the constant scan accuracy shown in
Section 11.2.
• When maximum processing time of one instruction exceeds 0.5ms
The constant scan time may increase by an excess over 0.5ms.
Also, PRG. TIME OVER (error code: 5010) is detected.
Refer to the following manual for the maximum processing time of one instruction.
QCPU (Q Mode)/QnACPU Programming Manual (Common
Instructions)
(b) When interrupt program/fixed scan execution type program is
Note6.4
executed
Interrupt is enabled while an interrupt program/fixed scan execution type program
is executed. If constant scan time runs out when an interrupt program/fixed scan
execution type program is executed, constant scan cannot be finished. When an
interrupt program/fixed scan execution type program is used, constant scan time
could be shifted by the execution time of an interrupt program/fixed scan
execution type program.
Figure 3.31,Figure 3.32)
Note6.4
Note3
6.2 Constant scan
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