08 performs a loop back test, Function, Message (for normal operation) – Yokogawa JUXTA VJ Series Limit Alarms User Manual
Page 47: Response (for normal operation), Example
<5. MODBUS Communication >
5-7
IM 77J01J11-01E
3rd Edition : Oct. 15, 2007-00
08
Performs a loop back test.
●
Function
This function code is used to check the connection for communication.
•
For the format of responses in the event of failure, see subsection 5.2.2.
•
The element marked with * is "00" (fixed).
•
Any value can be selected to send data.
●
Message (for normal operation)
2
1
1
None
4
2
2
1
Number of bytes in RTU mode
Number of bytes in ASCII mode
2
4
Address
Number
(ADDRESS)
Start of
Message Mark
(:)
Element
Function
Code (08)
00*
0000
Send Data
(any)
050216E.EPS
Message (continued)
Error
Check
End of Message
Mark (CR+LF)
None
2
2
2
●
Response (for normal operation)
2
1
1
None
4
2
2
1
Number of bytes in RTU mode
Number of bytes in ASCII mode
2
4
Address
Number
(ADDRESS)
Start of
Message Mark
(:)
Element
Function
Code (08)
00
0000
Same as
send data
050217E.EPS
Response (continued)
Error
Check
End of Message
Mark (CR+LF)
None
2
2
2
●
Example:
Sending data "1234h" in hexadecimal to the VJ Series signal conditioner with communica-
tion address 1 to check connection for communication.
The following message sends "1234" (hexadecimal) to communication address 1 in the
ASCII mode.
[Message]
: 010800001234B1[CR][LF]
Start of message mark
When connection for communication is normal, the response whose configuration is the
same as that of the message is returned with respect to the above message.
[Response]
: 010800001234B1[CR][LF]