Communications Using A Random Access Buffer Cannot Be Performed - Mitsubishi Melsec-L Series User Manual

14.6.7
Communications using a random access buffer cannot be
performed.
The following table lists how to troubleshoot the problem when an E71 cannot perform communications using a
random access buffer.
Check item
Has the connection with the connected device been opened?
(Check the corresponding bit of 5000
Did the connected device send a command?
Was a response returned to the device that had sent the
command?
Is the end code of the response 0?
Is the correct buffer memory address specified for the
command?
Has data been set in the specified address of the random
access buffer?
Has the write data been set in the connected device?
Has an open or initial error occurred in the error log area?
If the action above does not solve the problem, perform the following tests on the E71 to check for hardware error.
• Hardware test (
• Self-loopback test (
• Open the connection with the connected device.
• Check if the open/close process for I/O signals and the OPEN/CLOSE
in the buffer memory.)
instructions are used together for the same connection. If so, correct the
H
program.
Send a command to the E71.
• Check if the correct IP address was specified in the command. If not,
correct the IP address and send the command again.
• Check if the communication protocol (TCP/IP or UDP/IP) matches with
that of the connected device. If not, correct it.
Check the end and error codes to correct the error.
Correct the buffer memory address and send the command again.
Write the data.
Set the data.
Check and correct the error.
Page 266, Appendix 5.2)
Page 265, Appendix 5.1)
CHAPTER 14 TROUBLESHOOTING
Action
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