3-34
3.8 Precautions on Programming
3.8
Precautions on Programming
The following cases cause an operation error during the execution of basic instructions and
application instructions in a CPU module.
• Errors described on each page of instruction explanation are occurred.
• No intelligent function module is mounted at the specified I/O number position when an
intelligent function module device is used.
• The specified buffer memory address does not exist when an intelligent function module
device is used.
• The corresponding network does not exist when a link device is used.
• No network module is mounted at the specified I/O number position when a link device is used.
• A CPU module is not mounted at the start I/O number position of the specified CPU module
when a cyclic transmission area device is used.
• The specified shared memory address does not exist when a cyclic transmission area device
is used.
When setting file registers but a memory card is not installed, or when writing/
reading data to/from file registers without setting file registers results as follows.
(1) For High Performance model QCPU
An error does not occur even when writing/reading data to/from file registers.
However, "0
H
" is stored when reading from file registers.
(2) For Universal model QCPU
The OPERATION ERROR (error code: 4101) occurs when writing/reading
data to/ from file registers.
(1) Device range check
The following explains how the range is checked for devices used in basic instructions and
application instructions in a CPU module.
(a) Instructions that handle fixed-length devices (such as MOV or DMOV)
1) For CPUs other than the Universal model QCPU
The device range is not checked.
If the data exceed the corresponding device range, the data are written to another
devices.
*1
For example, when the data registers are assigned in 12k points, an error does not
occur even if the data exceed D12287.
The device range is not checked when the index setting is applied.
If the result of the index setting exceeds the corresponding device range, the data are
written to another devices.
*1
*1 : For the assignment order of internal user devices, refer to (c) in this section.
DMOV
EN
ENO
d
s
D
122
87
1
00
X
0
T
h
is s
p
eci
f
ies D
122
87 and D
122
88 as t
h
e
target devices
f
or executing t
h
e DMOV instruction
Ho
w
ever, since D
122
88 does not exist,
data in anot
h
er device is corru
p
ted.
Summary of Contents for MELSEC Q Series
Page 1: ...Structured Programming Manual Mitsubishi Programmable Controller QCPU Common Instructions ...
Page 2: ......
Page 14: ...A 12 MEMO ...
Page 340: ...6 178 MEMO MTR ...
Page 708: ...7 368 MEMO ...
Page 776: ...8 68 MEMO ...
Page 796: ...9 20 MEMO ...
Page 804: ...App 8 MEMO ...
Page 812: ...Index 8 MEMO ...
Page 815: ......