Mitsubishi Electric MELSEC iQ-R Series User Manual page 169

Remote password check
■How to unlock the remote password
• When C24 has been set as a subject to the remote password check with the CPU module parameter, a remote password
unlock processing must be performed from the target device after line connection before starting data communication.
• The unlock processing for the CPU module remote password is performed as follows:
When communicating using MC protocol: Perform the unlock processing from the target device using dedicated
commands.
■When the remote password unlock processing is completed abnormally
• Repeat the unlock processing after checking the remote password set in the CPU module.
• Start with the line connect processing again if C24 'Connection' (X12) turns OFF due to the unlock processing abnormal
completion.
• Perform the line connect processing again after clearing the accumulated count stored in the following buffer memory when
the 'CH Error occurrence' (XE/XF) of C24 turns ON and the ERR LED lights up due to the unlock processing abnormal
completion.
(Target buffer memory)
'Accumulated count of unlock process abnormal completion' (Un\G8956)
(How to clear)
Write "0" to the relevant area of the buffer memory.
■When the number of times remote password mismatch occurs is large
• When the number of times notification of a remote password mismatch is received exceeds the 'Remote password
mismatch notification count designation' (Un\G8204) , C24 disconnects the line automatically. (The 'Connection' (X12) turns
OFF.)
After confirming the remote password registered in the CPU module and the remote password specified in the target
device, restart form the line connection.
• When the count exceeds the 'Remote password mismatch notification accumulated count designation'(Un\G8205), C24
performs the following processing every time the mismatch occurs (The line to the modem is not disconnected.)
An error code (7FE8H) is stored in the 'MC protocol send error code' (Un\G602/618) on the buffer memory.
The 'CH Error occurrence' (XE/XF) turns ON and the ERR LED turns ON.
• The accumulated number of times remote password mismatch occurred up to the present time (accumulated count value
by C24) can be checked in the 'Accumulated count of unlock process abnormal completion' (Un\G8956).
• The accumulated number of times up to the present time should be cleared by writing "0" to the 'Accumulated count of
unlock process abnormal completion' on the buffer memory (Un\G8956).
• If the 'CH Error occurrence' (XE/XF) for C24 turns ON and the ERR LED turns ON, this may indicate
improper access from the target device. Refer to "CPU module side countermeasures against improper
access from a target device".
(Page 168 CPU module side countermeasures against unauthorized access from a target device)
• For details on how to turn OFF the ERR LED of C24, refer to the following manual.
(Page 448 Turning OFF the ERR LED and initializing the error codes)
7 COMMUNICATIONS BY THE MODEM FUNCTION
7.3 Specifications of Modem Function
7
167