Data Cannot Be Received With Communications Using A Fixed Buffer - Mitsubishi Electric QJ71E71-100 User Manual

16.5.9
Data cannot be received with communications using a fixed
buffer.
The following table lists how to troubleshoot the problem when an E71 cannot receive data with communications using
a fixed buffer.
Check item
Does the receive data length match with the amount of data
actually received?
Has the connection with the connected device been opened?
(Check the corresponding bit of 5000
Is the IP address setting of the connected device correct?
Does the communication protocol (TCP/IP or UDP/IP) match
with that of the connected device?
Is the reception completion signal of the corresponding fixed
buffer on? (Check the corresponding bit of 5005
buffer memory.)
Was the BUFRCV instruction executed?
Was the BUFRCV instruction completed normally?
Was the BUFRCVS instruction executed?
Is the control data of the BUFRCVS instruction correct?
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 (
If the amount of the actually received data is smaller than the receive data
length, receive the remaining data. If it is larger than the receive data
length, receive the excess data as the next request message or discard it.
• Open the connection with the connected device.
• Check if the open/close processes for I/O signals and the OPEN/CLOSE
instructions are not used together for the same connection. If so, correct
in the buffer memory.) the program.
H
• Read Open error code (address: 7C
storage area. Then check the error details and correct the error.
Check and correct the IP address of the connected device.
Use the same communication protocol (TCP/IP or UDP/IP) as that of the
connected device.
Data was not sent from the connected device. Check the connected device
in the
H
on the sending side and correct the error.
• Correct the execution conditions of the BUFRCV instruction.
• Check if the send/receive processes for I/O signals and the
BUFSND/BUFRCV instructions are not used together for the same
connection. If so, correct the program.
Check the error code in the BUFSND instruction completion status area
and correct the error.
• Correct the interrupt setting of the programming tool.
• Check if the send/receive processes for I/O signals and the
BUFSND/BUFRCV instructions are not used for the same connection. If
so, correct the program.
Correct the control data.
Check and correct the error.
Page 374, Appendix 6.2)
Page 373, Appendix 6.1)
CHAPTER 16 TROUBLESHOOTING
Action
) in the communication status
H
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