4
FUNCTIONS
4
- 4
4.2 Specifications on Cyclic Transmission Processing
4.2.1 Cyclic transmission processing
(3) When communication error or communication stop occurs on station
When a communication error station or a communication stop station is detected
during data link, other stations hold the data received from the station immediately
before the error occurrence.
("Communication stop station" is a station to which a peripheral device has stopped
cyclic transmission.)
(a) Normally communicating stations hold the data received from a communication
error station or a communication stop station.
(b) A communication stop station holds the data received from other stations.
(Example)
When a communication error occurred in 1N
S
2 due to cable disconnection
(4) SB/SW status when a communication error station/communication stop
station occurs
The status of whether there are any communication error/stop stations on the network
can be checked with the link special relay/register (SB/SW).
Use the link special relay and link special register shown in the following.
Section 11.1.1 Interlock related signals
For interlock program examples, refer to the following manual.
CC-Link IE Controller Network Reference Manual
Communication error station
Link data status after disconnection
Disconnected
Disconnected
Area in which link data are held
1N
S
3
1N
S
2
Link data
Link data
Link data
1N
P
1
1M
P
1
1M
P
1
1N
S
2
1N
S
3
1N
S
3
1M
P
1
1N
S
2
1N
S
2
1N
S
3
1M
P
1
1N
S
2
1N
S
3