Mitsubishi Electric MELSEC iQ-R C R12CCPU-V User Manual page 130

■No response received from a slave station
If the master station is unable to receive a response from a slave station due to power OFF or cable disconnection of the slave
station, the master station waits for a response from the slave station within the timeout time set in the link scan setting. If no
response is received within the specified number of times for disconnection detection, the master station disconnects the
slave station.
(1)
Lst
(4)
Lst
Ö
(4)
Lst
Ö
(4)
Lst
Ö
×
(Slave station disconnection detection setting: Timeout time = 500 ms, number of times = 3 times)
Lst: Link scan time (link scan)
(1) Master station
(2) Slave station 1
(3) Slave station 2
(4) Additional 100 ms
 The master station sends a request to the slave station 1 and slave station 2.
 The slave station 1 returns a response to the master station.
 The slave station 2 returns a response to the master station.
 The slave station 2 cannot return a response to the master station due to an error such as power OFF or cable
disconnection of the slave station.
 The master station waits for a response from the slave station 2 until the timeout time elapses, and then send a request to
the slave station 1 and slave station 2 because the master station cannot receive a response from the slave station 2. Note
that the link scan time is extended by the timeout time.
 The master station disconnects the slave station 2 because the master station cannot receive a response from the slave
station 2 within the specified number of times (three times) for the disconnection detection.
The operations of special relays and special registers when a slave station which did not send a response is disconnected are
as follows:
Special relay/special register
'Cyclic transmission status' (SM1536)
'Cyclic transmission status of each station' (SD1536 to
SD1539)
'Data link status' (SM1540)
'Data link status of each station' (SD1540 to SD1543)
7 CC-Link IE Field Network Basic FUNCTION
128
7.1 Cyclic Transmission Function
(2)
Ò
Ó
Ò
Ó
Ò
Ó
Ò
Ó
Ò
Operation
The device remains ON.
The bit corresponding to the station number of the disconnected slave station turns OFF.
The device turns OFF and ON.
The bit corresponding to the station number of the disconnected slave station turns ON (indicating
that the slave station is an error station).
(3)
Ô
Õ