Communication Error "Pro - Mitsubishi Electric QJ71C24N User Manual

11 TROUBLESHOOTING

11.3.10 Communication error "PRO."

Symptom
• Communications were
• Some of the data are
• Designated command does
• The device No. designation
• The characters in the
• Communication error
signal "PRO" turned
on.
• A device No. outside the
• A remote RUN/STOP
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Cause
performed with a control
procedure different from the
Q series C24 communication
protocol setting.
different from the control
procedure.
not exist.
is not the character count
corresponding to the
command.
message include a data
other than the "A to Z", "0 to
9", " ", and control data.
designated range was
designated.
request was issued while
remote STOP was applied
from another module.
Corrective action
• Check the Q series C24 communication protocol
setting and the message from the external device
and match the settings, or correct the message and
restart data communications.
• Use the communication monitoring function to check
the message from the external device.
• Check and correct the external device message and
restart data communications.
• Use the communication monitoring function to check
the message from the external device.
Note
• Only the data "0 to 9" and "A to F" can be handled
as character area data during communications
using an MC protocol (ASCII mode). Therefore,
when transmitting a character string as data,
convert the ASCII code of each character string to
2-byte binary code.
Examples)
• Transmitting the character "G"
The ASCII code for the character "G" is 47
is transmitted as the two bytes 34
• Transmitting the character "A"
The ASCII code for "A" is 41
as the two bytes 34 , 31
H
If the ASCII code 41
H
"A" is transmitted unchanged, the Q series
C24 ASCII-BIN conversion will convert it to
A (10) and pass it to the programmable
H
controller CPU.
• When designating a device, check "Device setting"
of the parameters written to the CPU and correct it to
a device No. within the designated range and restart
data communications.
• Check if remote STOP is applied from another
module and restart data communications.
and
H
, 37 .
H H
and is transmitted
H
.
H
for the character
MELSEC-Q
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