Return Bus Message Count (Sub-Function Code: 11) - Mitsubishi Electric QJ71MB91 User Manual

4
MODBUS STANDARD FUNCTIONS

4.11.7 Return bus message count (sub-function code: 11)

Reads out the number of messages detected on the line to the master.
(1) Request message format (Master
(2) Response message format (Slave
4
- 35 4.11 Diagnostics (FC: 08)
4.11.7 Return bus message count (sub-function code: 11)
Function code
Sub-function code
Function
Sub-function code
code
(000B
(08 )
H
(H)
Figure 4.42 Return bus message count (Request message)
(When completed normally)
Function code Sub-function code
Function Sub-function code
code
(000B
(08 )
H
(H)
The QJ71MB91 returns the bus message count value of the
buffer memory to the master. (address: 0F00
Figure 4.43 Return bus message count (Normal response message)
* 1 Refer to the following for the relevant counts, count clear methods and precautions.
Section 11.3
(When completed with an error)
Function code
Data
Function
Exception
code
code * 2
(88 )
H
Figure 4.44 Return bus message count (Exception message)
* 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
Slave)
Data
(0000
)
H
(L)
(H)
Master)
Data
Bus message count value
) (0000 to FFFF
H H
(L)
(H)
/0F40 )
H H
)
H
(L)
) * 1
H
(L)