YASKAWA GA700 Series Technical Manual page 284

6.3 MEMOBUS/Modbus Communications
Byte Command Message
2
Starting No.
3
4
Data Qty
5
6
CRC-16
7
8
9
10
11
12
■
Loopback Test
The loopback test uses function code 08 (Hex.) and returns the command message as a response message. This
test checks communication between the master and slave. The test code and data can use desired values.
Table 6.8 shows examples of messages given out when the loopback test is done with the drive of slave 1.
Byte Command Message
0
1
2
Test code
3
4
Data
5
6
CRC-16
7
■
Writing to Multiple Holding Registers
You can write the data that you set to the number of holding registers set in function code 10 (hex). You must
configure the number of the holding registers and each 8 higher bits and 8 lower bits in order in the command
message for the write data. You can write to a maximum of 16 holding registers.
Table 6.9 shows example messages when you use the PLC to set Forward run in the drive of slave 1 with a 60.00
Hz frequency reference.
When you rewrite the parameter value with the write command through the H5-11 [Comm ENTER Command
Mode] setting, you must use the Enter command to save and enable the contents of the changes. Refer to
Comm ENTER Command Mode on page 862
Table 6.9 Message Example When Writing to Multiple Holding Registers
Byte Command Message
0 Slave address
1 Function code
2
Starting No.
3
4
Data Quantity
5
6 Byte No.
7
First data
Data Quantity
8
284
Setting Data
Response Message (Normal)
(Hex.)
Upper 00
Lower 20
First storage
Upper 00
Lower 04
Next storage
Upper 45
Lower F0
Next storage
-
-
Next storage
-
-
-
Table 6.8 Message Examples from the Loopback Test
Setting Data (Hex.)
Slave address
Function code
Upper
Lower
Upper
Lower
Upper
Lower
and
Setting Data
Response Message (When
(Hex.)
01
10
Upper 00
Starting No.
Lower 01
Upper 00
Data Quantity
Lower 02
04
Upper 00
Lower 01
Setting Data
(Hex.)
Data Qty
Upper
register
Lower
Upper
register
Lower
Upper
register
Lower
Upper
register
Lower
Upper
CRC-16
Lower
Response Message (Normal)
01
08
00
Test code
00
A5
Data
37
DA
CRC-16
8D
Enter Command on page 287
Setting Data
Normal)
(Hex.)
Slave address
Function code
Upper
Lower
Upper
Lower
Upper
CRC-16
Lower
-
YASKAWA SIEPC71061705H GA700 Series Technical Manual
Response Message (Fault)
08 Error code
00 Upper
CRC-16
65 Lower
00 -
00 -
00 -
00 -
01 -
F4 -
AF -
82 -
Slave address
Function code
Upper
Lower
Upper
Lower
Upper
Lower
for more information.
Response Message (When
There is a Fault)
01 Slave address
10 Function code
00 Error code
01 Upper
CRC-16
00 Lower
02 -
10 -
08 -
-
Setting Data
(Hex.)
03
F1
31
Setting Data (Hex.)
01
08
00
00
A5
37
DA
8D
H5-11:
Setting Data
(Hex.)
01
90
02
CD
C1