4
MODBUS(R) STANDARD FUNCTIONS
4.1 MODBUS(R) Standard Function Support List
4 - 4
1
OVERVIEW
2
SYSTEM
CONFIGURATION
3
SPECIFICATIONS
4
MODBUS(R) STANDARD
FUNCTIONS
5
FUNCTION
6
PRE-OPERATIONAL
PROCEDURES AND
SETTINGS
7
PARAMETER SETTING
8
UTILITY PACKAGE
(GX Configurator-MB)
* 1 The slave function of the QJ71MB91 does not support this function.
( This section (2))
Remark
The usable functions are limited when the QJ71MB91 is installed to a
MELSECNET/H remote I/O station.( This section (3))
Table 4.1 MODBUS standard function support list (continued)
Function
code
(Sub code)
Sub-function
code
Function Description
Accessible
devices per
message
Broadcast Reference
16 - Write multiple registers
Writes values to multiple holding
registers.
1 to
123 points
Section
4.15
17 - Report slave ID
Acquires the information of the slave
(QJ71MB91) mounted station into the
master.
-
Section
4.16
20(6) - Read file record
Reads values of one or more extended
file registers.
1 to
124 points
Section
4.17
21(6) - Write file record
Writes values to one or more extended
file registers.
1 to
122 points
Section
4.18
22 - Mask write register
Masks the values stored in a single
holding register with AND or OR and
writes the value.
1 point
Section
4.19
23 -
Read/Write multiple
registers
Reads from or writes to multiple holding
registers.
Read:
1 to
125 points
Write:
1 to
121 points
Section
4.20
24
*1
- Read FIFO queue
Reads values from the holding
registers in FIFO queue structure.
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43
*1
-
Read device
identification
Reads the module identification
information of the slave.
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