Advertisement
4-4-4 Echoback Test
Command Frame
Slave
Function
address
code
H'08
1
1
Response Frame
Slave
Function
address
code
H'08
1
1
Note: When the command is executed normally, the response returns the same data sent in the command.
(1) Test Data
Enter any 2-byte hexadecimal data.
(2) Response Code
Function code
'
H
88
'
H
08
(3) Example Command and Response
The following example shows the command/response for an Echoback Test command.
(In this case, the test data is H'1234.)
(In this case, the slave address is H'01.)
Command:
Response:
E5@D Digital Temperature Controllers Communications Manual (H225)
Test data
Fixed data
H'00
H'00
2
2
Fixed data
Test data
H'00
H'00
2
2
Error
Name
code
'
Variable data error
H
03
---
Normal completion
01
08
00 00
12 34
ED 7C(CRC-16)
01
08
00 00
12 34
ED 7C(CRC-16)
4 Modbus Communications Procedure
CRC-16
2 bytes
CRC-16
2 bytes
Description
A different value (not H
returned.
No errors were found.
4
'
'
00, H
00) was
4 - 15
Advertisement
