YOKOGAWA UTAdvanced Series, User Manual

Page: 91 / 866

4-14
IM 05P07A01-01EN
4.4.4 Response Error Codes

When a response is returned to a request:
When the PDU in the request contains an inconsistency, the UT75A/UT55A/UT35A/
UP55A/UP35A does not perform any processing, and returns the following request.
Element MBAP Header PDU
Number of bytes 2 2 2 1 1 1
Command
element
Transfer ID Protocol ID Number of
bytes
Unit ID Function
code*
Error Code
(Hex) Optional value 0000 03 01
* The value of “function code (Hex) + 80 (Hex)” is set in the function code.

Response error codes
Error Code Meaning Cause
01 Function code error The function code does not exist.
02 D register/I relay No. error A No. outside the range has been specified.
03
Number of D registers/
I relays error
A number of registers/relays outside the range has been specified.
09 Monitor not specified An attempt was made to read a monitor without specifying the monitor.

When a response is not returned to a request
In the following instances, the UT75A/UT55A/UT35A/UP55A/UP35A does not perform
any processing and does not return a response:
• When a connection has not been established on the TPC/IP socket interface
• When the MBAP Header in a request contains an inconsistency
* As a measure for the above, execute time-out processing by the communication function or
communication program on the host computer.
4.4 Communication with Host Computer