Mitsubishi MELSEC LJ71C24, User Manual

Page: 316 / 428

15 - 47 15 - 47
15 TROUBLESHOOTING
Symptom Cause Corrective action MC
Bi
di
re
ct
io
na
l
N
on-
procedural
Predefined
• The user-edited protocol
setting in the predefined
protocol support function
of GX Works2 is
inconsistent with the
packet format of the
external device.
• Check the packet format of the external
device, and correct the protocol setting.
(1) When a conversion variable exists in the
receive packet, check for an error in the
setting of Conversion, Sign character,
Number of decimals, Delimiter, or Number
of digits.
(2) When an error check code exists in the
receive packet, check for an error in the
setting of Processing method, Code type,
Data length, Data flow, Complement
calculation, or Calculating range.
(3) When Length exists in the receive packet
and a conversion variable is included in the
calculating range of the Length, check for
an error in Code type, Data length, Data
flow, or Calculating range set for the
Length.
• An expected packet was
not received, and a
monitoring timeout error
occurred.
• Using the circuit trace (communication data
monitoring function) of the predefined
protocol support function of GX Works2,
check for the data being transmitted from
the external device.
• When the predefined
protocol is executed,
the "ERR." LED turns
on.
• A communication error
occurs.
• Confirm the error by the system monitor,
and remove the cause of the error.
REMARKS
When the "ERR." LED is turned on, an error code is stored in the following buffer
memory.
Error code storage buffer memory
Address
Error cause
CH1 CH2
Name
Switch setting error
Mode switching error
203
H
Switch setting error and mode switching
error status
On-demand execution error 256
H
266
H
On-demand execution result
Data transmission error 257
H
267
H
Data transmission result
Data receive error 258
H
268
H
Data reception result
Modern function error 221
H
Modern function error code
MC protocol transmission error 25A
H
26A
H
MC protocol transmission error code
Monitoring device error 2205
H
2305
H
Programmable controller CPU monitoring
function execution result
Predefined protocol function error 4042
H
4052
H
Predefined protocol function error code
For details of the error codes, refer to Section 15.2.