Mc Protocol Communications Cannot Be Performed - Mitsubishi Electric QJ71E71-100 User Manual

16.5.4

MC protocol communications cannot be performed.

The following table lists how to troubleshoot the problem when the E71 cannot perform MC protocol communications.
Check item
Has the connection with the connected device been opened?
(Check the corresponding bit of 5000
*1
memory.)
Did the connected device send a command?
Was a response returned to the device that had sent the
command?
Does the communication protocol (TCP/IP or UDP/IP) match
with that of the connected device?
Does the communication data code (ASCII or binary) setting
match with that of the connected device?
Is the end code of the response 0?
Is the correct command format used for the command type,
device, address, and others?
Is the write operation during RUN enabled?
Has an open or initial error occurred in the error log area?
*1 If the connection of only the connected device is closed due to cable disconnection, personal computer restart, or other
reasons, reopen the connection using the same port used before the error occurred. The E71 does not close a
connection if it receives an Active open request again from the connected device with a different IP address or a port
number.
*2 If the communication data code setting is different between the E71 and the connected device, error codes that are not
found in the error code list may be returned to the connected device. When receiving data with different data codes, the
E71 cannot decode commands normally. The E71 returns an error response according to the communication data code
setting. (
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
H
instructions are not used together for the same connection. If so, correct
the 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.
Use the same communication protocol (TCP/IP or UDP/IP) as that of the
connected device.
If the data code settings do not match, data cannot be sent or received
because the connected device cannot normally decode commands.
the same setting of "Communication Data Code" in the Ethernet operation
setting as that of the connected device.
(
Check the end and error codes to correct the error.
Correct the command format.
Check the checkbox next to "Enable Write at RUN time" in the Ethernet
operation setting.
Check and correct the error.
Page 155, Section 12.6.2 (1) (e), Remarks)
Page 374, Appendix 6.2)
Page 373, Appendix 6.1)
Action
Page 84, Section 7.1.3)
CHAPTER 16 TROUBLESHOOTING
*2
Use
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