Get Communications Event Counter (Fc: 11) - Mitsubishi Electric QJ71MB91 User Manual

4
MODBUS STANDARD FUNCTIONS

4.12 Get Communications Event Counter (FC: 11)

Acquires the number of messages whose requested actions (read/write, diagnostics, etc.)
have been normally completed.
Whether the action corresponding to the request message is normally completed or not
can be checked.
(1) Request message format (Master
Figure 4.71 Get communications event counter (Request message)
(2) Response message format (Slave
4
- 45 4.12 Get Communications Event Counter (FC: 11)
Function code
Function
code
(0B )
H
(When completed normally)
Function code
Function Program command status
code
(0000
(0B )
H
(H)
The QJ71MB91 stores the communications event count value of the buffer
memory as the communications event count value. (address: 0F0B
Figure 4.72 Get communications event counter (Normal response message)
* 1 Since the QJ71MB91 does not support any program commands, 0000
* 2 The count is stopped if it has reached FFFF
Reset the counter by either of the following methods when restarting the count.
Clearing the counter and diagnostic register (
Restart communications option (
Power OFF
POINT
The communications event counter counts only when the processing (read/write,
diagnostics, etc.) has completed normally.
The communications event counter does not count in the case of the following:
• The processing has completed with an error.
• When receiving a request message containing a function code that the
QJ71MB91 does not support
• When receiving the Get communications event counter (FC: 11) and Get
communications event log (FC: 12)
Slave)
Master)
Data
Communications
1
) *
event count value
H
(0000
(L)
(H)
.
H
Section 4.11.2)
ON, or programmable controller CPU reset
to FFFF ) * 2
H H
(L)
/0F4B )
H H
is stored.
H
Section 4.11.6)