Mitsubishi QJ71MB91 User Manual

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11.3 Checking the Communication Status of QJ71MB91
11
TROUBLESHOOTING
11.3 Checking the Communication Status of QJ71MB91
The QJ71MB91 counts the number of times that errors occur during communication.
The communication status of QJ71MB91 can be checked by this counter (diagnostic
counter).
(1) Diagnostic counter
(a) Master function
Table11.9 List of diagnostic counters (Master function)
Item Description
Buffer memory
CH1 CH2
Bus message count
Counts the number of messages sensed on the line.
The bus message count is in an exclusive relationship with the bus
communication error count.
0F00
H
(3840)
0F40
H
(3904)
Bus communication error count
Counts the number of error messages sensed on the line.
"Error messages" include the following:
• CRC/LRC error message
• Overrun/parity error
• Short frame (less than 3 bytes)
• Character overrun (256 bytes or more)
Messages other than the above are counted by the bus message count.
(The bus communication error count is in an exclusive relationship with
the bus message count.)
0F01
H
(3841)
0F41
H
(3905)
Received exception error count
Counts the number of times that exception errors are received.
(excluding the case of broadcast)
0F0E
H
(3854)
0F4E
H
(3918)
Received NAK count
*1*2
Counts the number of times that NAK responses were received from
slaves.
0F11H
(3857)
0F51
H
(3921)
Received busy count
*2
Counts the number of times that busy responses were received from
slaves.
0F12H
(3858)
0F52
H
(3922)
Character overrun error count
Counts the number of times that the request message size exceeded the
upper limit.
0F02
H
(3842)
0F42
H
(3906)
Message discard count
Counts the number of times that a response message was discarded, for
example, when a message from an unexpected station number was
received.
0F03
H
(3843)
0F43
H
(3907)
Data discard count
Counts the number of times that illegal data (e.g. frames not configured in
the stipulated response message format) was discarded.
0F04
H
(3844)
0F44
H
(3908)
Failed transmission count
Counts the number of times that transmission of request messages
failed. (e.g. when no cable is connected)
0F05
H
(3845)
0F45
H
(3909)
No-response count
Counts the number of times that there was no response from a slave
after request message transmission. (Number of response monitoring
timer timeouts)
It does not count for broadcast request messages.
0F0F
H
(3855)
0F4F
H
(3919)
Broadcast count Counts the number of times that request messages were broadcast.
0F10
H
(3856)
0F50
H
(3920)

Mitsubishi QJ71MB91 Specifications

General

Brand	Mitsubishi
Model	QJ71MB91
Category	Controller
Language	English