Mitsubishi MELSEC-A Series Programming Manual page 272

7. APPLICATION INSTRUCTIONS
Operation Errors
Program Examples
In the following cases, operation error occurs and the error flag turns on.
• Access cannot be made to the special function module.
• The I/O number specified at "n1" is not a special function module.
• "n3" points, which begin with the device specified at (D), exceeds the specified
device range.
TO
Program which sets three channels to the address 0 of buffer memory of A68AD,
loaded in I/O numbers 040 to 05F when X20 turns on.
X000
P H
0 TO 0004
DTO
The following program writes D1 value to A68AD (loaded in I/O numbers 040 to 05F)
buffer memory address 0 and D2 value to address 1 when X0 is switched on.
X000
P H
DTO 0004
0
POINT
If a TO instruction is executed for a special function module frequently in a
short scan time, the objective special function module may fail to process
correctly.
To execute a TO instruction for a special function module, set the execution
intervals meeting the processing and conversion time of that module using the
timer and the constant scan function of it.
• Coding
K K K
0
0 3 1
1
10
• Coding
K K
0
0 D1 1
1
12
7 − 70
MELSEC-A
LD X000
TOP H0004 K0
END
LD X000
DTOP H0004 K0
END
K3 K1
D1 K1