Mitsubishi QJ71MB91 User Manual page 57

4
MODBUS(R) STANDARD FUNCTIONS
Function
Sub-function
code
code
(Sub code)
00 Return query data
Restart communications
01
option
Return diagnostic
02
register
Change ASCII input
03
delimiter
04 Force listen only mode
08
Clear counters and
10
diagnostic register
Return bus message
11
count
Return bus
12 communication error
count
Return bus exception
13
error count
Return slave message
14
count
Return slave no
15
response count
Table4.1 MODBUS standard function support list (continued)
Function
Returns the contents of the request
message without change.
Used to check if the network or the
target device is operating normally.
(Loopback test)
Initializes the communication port of the
receiving channel side and restarts the
slave function. (Clears counters such
as the message count.)
Returns to the online mode when it is in
the listen only mode.
Reads out the detailed LED status of
the QJ71MB91 to the master.
Changes the 2nd byte (LF(0A
end code in the ASCII mode to a
specified data.
Places a slave into the offline mode.
Used when disconnecting a slave from
the network.
Clears counters (e.g. message count).
Also, clears the diagnostic register and
the error of the channel where the
request message has been received.
Reads out the number of messages
detected on the line to the master.
Reads out the number of error
messages detected on the line to the
master.
Reads out the frequency of exception
errors to the master.
Reads out the number of the slave
message processing to the master.
(Including reception of broadcast
request messages)
Reads out the number of broadcast
request messages received to the
master.
4.1 MODBUS(R) Standard Function Support List
Accessible
devices
Description
message
)) of the
H
Broadcast Reference
per
Section
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4.11.1
Section
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4.11.2
Section
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4.11.3
Section
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4.11.4
Section
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4.11.5
Section
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4.11.6
Section
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4.11.7
Section
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4.11.8
Section
-
4.11.9
Section
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4.11.10
Section
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4.11.11
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