Mitsubishi Electric Q01UCPU User Manual page 230

(2) Items disabled when the high-speed interrupt function is used
Item
External input/output forced on/off
Index register
Local device
File register having the same name as a program
Device comment having the same name as a program
(3) Time required for one interrupt program
If exceeded, "WDT ERROR" may occur and the operation of the high-speed interrupt program is not guaranteed.
(4) "Interrupt Program/Fixed Scan Program Setting" in PLC parameter
For high-speed interrupts, the "High Speed Execution" parameter setting is ignored even when selected.
(5) High-speed I/O refresh function and high-speed buffer transfer function
• Mount the target modules of these functions on the main base unit.
• When the high-speed buffer transfer function is executed, an error does not occur even when the file register
is used exceeding the setting range. Data out of the setting range, however, are not transferred. (There is no
impact on other device data.)
(6) Programming precautions
Refer to the programming precautions for interrupt programs. (
(7) Occurrence of the same interrupt
If the same interrupt factor occurs while a high-speed interrupt program (I49) is being executed, the second
interrupt will be ignored.
228
Operation when used
This function is not executed and ignored in high-speed interrupt programs. (No error
occurs.)
High-speed interrupt programs do not save nor restore data in the index register. If data in
the index register are changed in a high-speed interrupt program, the data are
overwritten.
High-speed interrupt programs do not save nor restore data in local devices. If data in
local devices are changed in a high-speed interrupt program, the data are overwritten in
the program that was being executed before the interrupt.
High-speed interrupt programs do not automatically change the file register name to the
same name as a program. If data in the file register are changed in a high-speed interrupt
program, the data are overwritten in the program that was being executed before the
interrupt.
High-speed interrupt programs do not automatically change the device comment file
name to the same name as a program. The following data are not updated in a high-
speed interrupt program.
• Comment use (SM650)
• Comment drive (SD650)
• Comment file name (SD651 to SD656)
• Memory card in-use flag (SM604)
• Memory card use conditions (SD604)
• Drive 3/4 in-use flag (SM624)
• Drive 3/4 use conditions (SD624)
Page 80, Section 2.9)