Mitsubishi QJ71MB91, User Manual

Page: 97 / 372

4
MODBUS(R) STANDARD FUNCTIONS
4.11 Diagnostics (FC: 08)
4.11.14 Return bus character overrun count (sub-function code: 18)
4
- 42
1
O
VER
VIE
W
2
SYS
T
E
M
CO
NF
IG
U
R
A
T
IO
N
3
S
P
E
CIFICA
TI
ONS
4
MODB
US
(R)
S
TA
NDA
RD
FUN
C
TIO
N
S
5
FUNC
TI
ON
6
PR
E
-O
PER
A
T
ION
AL
P
R
OCED
URE
S A
ND
SE
TTINGS
7
P
A
RA
MET
E
R S
E
TTI
N
G
8
UTIL
ITY P
A
CK
AGE
(G
X Co
nf
ig
u
rat
o
r-M
B)
4.11.14 Return bus character overrun count (sub-function code: 18)
To the master, reads out the number of times the request message size exceeds the upper
limit.
(1) Request message format (Master Slave)
(2) Response message format (Slave Master)
(When completed normally)
* 1 Refer to the following for the relevant counts, count clear methods and precautions.
Section 11.3
(When completed with an error)
* 2 Exception and error codes are stored in the buffer memory in the case of error completion.
Refer to the following for storage location, confirmation methods, and detailed contents.
Section 11.4
Remark
Refer to the following for the size of request messages.
Section 4.2.1
Figure 4.63 Return bus character overrun count (Request message)
Figure 4.64 Return bus character overrun count (Normal response message)
Figure 4.65 Return bus character overrun count (Exception message)
(L)
Data
(L)
Function code
Function
code
(08
H
)
Sub-function code
Sub-function code
(0012
H
)
(0000
H
)
(H) (H)
(L)
Data
(L)
Function code
Function
code
(08
H
)
Sub-function code
Sub-function code
(0012
H
)
Bus character overrun
count value
(0000
H
to FFFF
H
) *
1
The QJ71MB91 returns the bus character overrun count value
of the buffer memory to the master. (address: 0F02
H
/0F42
H
)
(H)
(H)
Data
Function code
Function
code
(88
H
)
Exception
code *
2