Mitsubishi Electric GT14 User Manual page 1524


Address
GT Designer3 converts the device numbers into
decimal format according to the address map of the
MODBUS equipment to be used.
The table below shows the representations on the
MODBUS/RTU communication protocol and GT
Designer3.
MODBUS/RTU Communication protocol
Function Code to
be used
Device name
Read Write
0x05
Coil 0x01
0x0F
Input relay 0x02 -
Input register 0x04 -
Holding 0x06
0x03
register 0x10
Extension file
0x14 0x15
register
POINT POINT POINT
Address conversion example
When monitoring the holding register's address
"1234H"
GT Designer3 displays "4*****" since GT Designer3
processes the internal conversion in decimal format as
follows:
GT Designer3 converts the holding register's address
"1234H" to "04660" in decimal format.
Then, "+1" is added to this decimal address since the
holding register's address on GT Designer3 always
starts from "1."
Therefore, the holding register's address "1234H" is
displayed as "404661" on GT Designer3.
Holding register
"4 04660" +1
63 - 8
63. MODBUS(R)/RTU CONNECTION
63.5 MODBUS/RTU Equipment Side Setting
Representation on GT
Designer3
Address
0000 000001
0001 000002
to to
FFFE 065535
FFFF 065536
0000 100001
0001 100002
to to
FFFE 165535
FFFF 165536
0000 300001
0001 300002
to to
FFFE 365535
FFFF 365536
0000 400001
0001 400002
to to
FFFE 465535
FFFF 465536
0000 600000
0001 600001
to to
270E 609998
270F 609999
1234H
"404661"

MODBUS communication control function on
the GS device
(1) Function overview
This function is to prevent the communication response
delay that occurs because the devices on the
MODBUS network differ from each other in network
specification.
This function is effective for the MODBUS network
conditions as described below:
• When only a part of function codes is supported
(Example: "0F" is not supported)
• When the maximum transfer size of function code is
small (Example: The maximum number of coil read
times is 1000)
(2) Communication settings
When the MODBUS/RTU communication driver is
assigned to multiple channel numbers using the multi-
channel function, the following cases are possible. The
communication settings are shared between the
assigned multiple channel numbers, or the individual
communication setting is configured to a specific
channel number.
By setting the device GS579, either the GS device used
for sharing communication settings (GS570 to GS576)
or the GS device used for individual communication
setting (GS590 to GS617) is validated.
GS
Description
device
Bit0: 0 Configure the Ch1 communication settings
between GS570 to GS576.
1 Configure the Ch1 communication settings
between GS590 to GS596.
Bit1: 0 Configure the Ch2 communication settings
between GS570 to GS576.
Validity of 1 Configure the Ch2 communication settings
setting between GS597 to GS603.
GS579
channel Bit2: 0 Configure the Ch3 communication settings
number between GS570 to GS576.
1 Configure the Ch3 communication settings
between GS604 to GS610
Bit3: 0 Configure the Ch4 communication settings
between GS570 to GS576.
1 Configure the Ch3 communication settings
between GS611 to GS617.
(a) When sharing communication settings between
multiple channel numbers
The table below shows the settings for the GS
device. The GS device can be changed even in the
middle of the operation.
GS
Description
device
GS570 Command selection
Function Code
"01"
GS571
Specification for the max.
number of coil read times
Function Code
"02"
GS572 Specification for the max.
number of input relay read
times
Set value
Set value
Bit0: 0 Using Function Code "0F"
1 Not using Function Code "0F"
Bit1: 0 Using Function Code "10"
1 Not using Function Code "10"
0: 2000
1 to 2000: Specify the maximum number.
Other than above: 2000
0: 2000
1 to 2000: Specify the maximum number.
Other than above: 2000