Return Bus Character Overrun Count (Sub-Function Code: 18) - Mitsubishi QJ71MB91 User Manual

4
MODBUS(R) STANDARD FUNCTIONS

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
Function code
(2) Response message format (Slave
(When completed normally)
Function code
(When completed with an error)
Figure 4.65 Return bus character overrun count (Exception message)
Remark
Sub-function code
Function
Sub-function code
code
(0012 )
H
(08 )
H
(H)
Figure 4.63 Return bus character overrun count (Request message)
Sub-function code
Function
Sub-function code
code
(0012 )
H
(08 )
H
(H)
The QJ71MB91 returns the bus character overrun count value
of the buffer memory to the master. (address: 0F02
Figure 4.64 Return bus character overrun count (Normal response message)
* 1 Refer to the following for the relevant counts, count clear methods and precautions.
Section 11.3
Function code
Data
Function
Exception
code
2
code *
(88 )
H
* 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
Refer to the following for the size of request messages.
Section 4.2.1
4.11.14 Return bus character overrun count (sub-function code: 18)
Slave)
Data
(0000 )
H
(L) (L)
(H)
Master)
Data
Bus character overrun
count value
(0000 to FFFF ) *
H H
(L) (L)
(H)
/0F42 )
H H
4.11 Diagnostics (FC: 08)
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