Mitsubishi Electric L02SCPU User's Manual And Reference page 382

(a) Overhead time at execution of interrupt and fixed scan execution type programs
When using an interrupt or fixed scan execution type program, add the overhead time given in the following
table. Two kinds of overhead time (pre-start and program-end) need to be added to interrupt programs.
CPU module
L02SCPU,
L02SCPU-P
L02CPU, L02CPU-P
L06CPU, L06CPU-P,
L26CPU, L26CPU-P,
L26CPU-BT,
L26CPU-PBT
L02SCPU, L02SCPU-P
L02CPU, L02CPU-P
L06CPU, L06CPU-P, L26CPU, L26CPU-P, L26CPU-BT,
L26CPU-PBT
L02SCPU, L02SCPU-P
L02CPU, L02CPU-P
L06CPU, L06CPU-P, L26CPU, L26CPU-P, L26CPU-BT,
L26CPU-PBT
(b) Overhead time when local devices in the interrupt program are enabled
Add the overhead time given in the following table when use of local devices is enabled in the interrupt program
by turning on SM777 (Enable/disable local device in interrupt program).
[Pre-start overhead time for interrupt programs]
(N1  KM1) + ((N2 + (N3  16))  KM2) + KM3 [s]
[Overhead time after interrupt program activation]
(N1  KM4) + ((N2 + (N3  16))  KM5) + KM6 [s]
• N1: Number of devices that is specified as a local device (The index register is excluded.)
• N2: Number of word device points (The index register is excluded.)
• N3: Number of bit device points
L02SCPU, L02SCPU-P
L02CPU, L02CPU-P
L06CPU, L06CPU-P, L26CPU, L26CPU-P, L26CPU-BT,
L26CPU-PBT
380
Pre-start overhead time for interrupt programs
Interrupt from the built-in I/O
(I0 to I15)
Without high- With high-
speed start speed start
65.0 [s] 31.0 [s]
57.0 [s] 19.0 [s]
54.0 [s] 18.0 [s]
CPU module
CPU module
CPU module
Fixed scan interrupt (I28 to
I31)
Without high- With high-
speed start speed start
55.0 [s] 35.0 [s]
51.0 [s] 17.0 [s]
46.0 [s] 16.0 [s]
Program-end overhead time for interrupt programs
Without high-speed start
28.0 [s]
28.0 [s]
26.0 [s]
Overhead time for fixed scan execution type programs
Without high-speed start
92.0 [s]
77.0 [s]
72.0 [s]
KM1 KM2 KM3
13.2 0.22 210.0
8.0 0.22 90.0
8.0 0.10 80.0
Interrupt from the intelligent
function module (I50 to I127)
Without high- With high-
speed start speed start
76.0 [s] 55.0 [s]
66.0 [s] 31.0 [s]
61.0 [s] 26.0 [s]
With high-speed start
15.0 [s]
9.0 [s]
8.5 [s]
With high-speed start
60.0 [s]
25.0 [s]
23.0 [s]
KM4 KM5 KM6
8.0 0.23 30.0
8.0 0.22 30.0
8.0 0.10 20.0