Using The Link Special Relays (Sb)/Link Special Registers (Sw) - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

6 PROGRAMMING

6.4 Using the Link Special Relays (SB)/Link Special Registers (SW)

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The data linking information is stored in the link special relays (SB)/link special
registers (SW).
They can be used by the sequence programs, or used for investigating faulty areas
and the causes of errors by monitoring them.
For details, refer to Appendixes 3 and 4.
(1) Cyclic transmission stop/restart
Cyclic transmission stop/restart is executed through the GX Developer network
tests, but it also can be executed with link special relay (SB) and link special
register (SW). Refer to Section 7.8)
(a) Cyclic transmission stop/restart
(Cyclic transmission stop)
1) In the following link special register (SW), specify a station for
stopping cyclic transmission.
• Specification of target station
Link stop/startup direction content (SW0000)
• Specification of station No.
Link stop/startup direction content (SW0001 to SW0004)
2) Turn System link stop (SB0003) ON.
3) When the network module accepts a request, Cyclic transmission
stop acknowledgment status (system) (SB0052) is turned ON.
4) When the cyclic transmission stop is completed, Cyclic transmission
stop completion status (system) (SB0053) is turned ON.
5) The station No. of the station that performed the cyclic transmission
stop request is stored in Data linking stop request station (SW004A).
(Saved in the station which received the stop request.)
6) If the cyclic transmission stop is completed abnormally, an error code
will be stored in Data linking stop status (entire system) (SW0053).
7) Turn System link stop (SB0003) OFF.
MELSEC-Q
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