Specifications

5 - 5
(b) The interrupt sequence program of the host's CPU module can be started up
using the event issue function.
This function reduces the response time of the system and enables the
real-time data reception.
END
MAIN
I50
CPU module Network module
Cyclic transmission
MELSECNET/H
Normal
sequence
program
Condition check
Interrupt condition
parameters
Relay information
Register data
Network status
Conditions
matched
Interrupt
sequence
program
IRET
(4) Enhanced RAS functions
(a) When a faulty station recovers and can resume the normal operation, it
automatically returns to the network to resume the data communication using
the automatic return function.
(b) By using the loopback function (the optical loop system), it is possible to
continue data transmission among operational stations by disconnecting faulty
areas such as a part of the network where there is a cable disconnection, a
faulty station, etc.
(c) By using the station detach function (coaxial bus system), even when some of
the connected stations are down due to the power off, etc., the normal
communication can continue among the other operational stations.
(d) The network module can continue the transient transmission even if an error
that stops the CPU module while the system is operating occurs.
(e) It is possible to check the time when a transient error has occurred.
Remark
The following faults make the RAS functions valid.
• Break in a cable
• Power-off of a slave station
• Network setting error
• Fault detectable by the self-diagnostics of a CPU module
If the network module has become faulty, the RAS functions may not be activated
depending on the fault.