Mitsubishi Electric QJ71C24N User Manual page 320

11 TROUBLESHOOTING
Status
No. signal Description
name
1 SD WAIT Transmission wait status
2 SIO SIO error status
3 PRO. Character error status
Status of parity error or
4 P/S
sum check error
Access status with the
5 C/N programmable controller
CPU
Abnormal completion
6 NAK
status
7 ACK. Normal completion status
Neutral status
8 NEU. Waiting to receive
command
Error occurrence status on
9 CH2. ERR
CH2 side
Error occurrence status on
10 CH1. ERR
CH1 side
11 - 4
(3) Checking by GX Configurator-SC
Have the "Monitor/test others" screen displayed.
For displaying the screen, see Section 9.6.10 of the User's Manual (Basic).
(4) LED ON status and communications error status
Description when ON
(when LED is turned
on (1))
Waiting for data
transmission
Overrun or framing
error occurred.
OS area is full.
Received data was
deleted.
Error occurred.
Error occurred.
( )
1
Abnormal completion
transmission
Normal completion
transmission
Neutral
Switch setting error
Mode switching error
Transmission error
Reception error
On-demand error
Flash ROM write error
Flash ROM write count
over limit error
1 C/N turns on in the following cases:
• An external device issued a data read request to the programmable controller
CPU when write during RUN is set to prohibit in the switch settings by GX
Developer (see Section 4.5.2).
For functions that cannot be used when write during RUN is set to prohibit, see
the explanation section in each command list of the Reference Manual.
• When an error has occurred during access between the Q series C24 and the
programmable controller CPU.
2 NEU. is valid when a target interface is set to use the MC protocol.
When the target interface is set to other than the MC protocol, the status of NEU.
is off.
Description when OFF
Initial
(when LED is turned
state
off (0))
Data transmission start OFF
OFF
Normal
OFF —
Normal OFF
Normal OFF
Normal OFF
Normal completion
OFF
transmission
Abnormal completion
OFF
transmission
(
Command reception
2
OFF
Normal
OFF
MELSEC-Q
Related protocol
Non
Bidirectional
MC
procedure
protocol
—
—
)
Pre-
defined
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