Mitsubishi Electric MELSEC-A User Manual page 156

16. TROUBLESHOOTING (MULTIDROP LlNK FUNCTIONS)
MELSEC-A
16. TROUBLESHOOTING (MULTIDROP LlNK FUNCTIONS)
This chapter describes errors which can occur with the multidrop functions.
16.1 Error Codes (Master Station)
During data transmission between the AJ71UC24 and slave stations appro-
priate error codes are written to buffer address 60H to define the error as
follows:
Error
Hexedeci
Description
Pretrans-
sequence
06H (6)
08H (8)
sion
sequence
16H (22)
Any of the followin
errors has occurre%
durina oretransmission
sequGce.
t
Initial data setting error
t
DIP switch setting error
t
Cable connection error
t
Data communication error
During communication
with station 2
During communication
1
wth statlon 6
During wmmunication
I
w t h statlon 7
During communication
I
w t h station 8
' 1
L2 ON
Xnl ON
Initial data has not been transferred from the buffer
memory to the RS-42.21485 interface transmission
buffer.
During communication
with station 1
During communication
with station 2
Any of the followin
errors has occurreg
during data transmission
sequence.
8
Cable error
I
Data communication error
During communication
with station 7
During communication
with station 8
Data cannot
be
transferred between the buffer
memory and the RS-42Z485 interface
communication buffer.
Initial data is wrong.
L2 ON
Xnl ON
Remedy
Check initial data.
Check DIP sw~tches.
Check slave station
power.
4
Check cable.
51
Check terminal resistor.
1)
Check the number of
FROMITO instructions.
2) Hardware fault
1) Check Slave station
power.
2) Check cable
1) Check the number of
FROMfTO instructions.
2) Hardware fault
Check initial data.
(See Section 13.3)
* I : When SW22 (setting of link processing(slave station is faulty)) turns ON
(continuation),
"L6"
LED turns ON, and Xn3 turns ON.