Yaskawa SI-ET3 - Manual (Page 21)

7 Transmission Interface
YASKAWA ELECTRIC SIEP C730600 62B 1000-Series Option SI-ET3 Technical Manual 21
‹ Communications Phases
The SI-ET3 changes status as described here when a command code or fault is received from the master.
Figure 10
Figure 11 Communication phases
„ Phase 1: Initial status after power ON
Operation proceeds with a default transmission cycle of 2 ms. The transmission cycle is changed to the time indicated in
the synchronous frame when a CONNECT command is received from the master. Then the phase moves to phase 2 or
phase 3 after a response to the CONNECT command is returned.
Even if a transfer fault is detected in phase 1, no fault notification is provided.
„ Phase 2: Asynchronous communications
All SI-ET3 commands can be used. Phase 2 starts to count the watchdog timer in the communications frame. The phase
moves to phase 3 when a SYNC_SET command is received, and it moves to phase 1 when a DISCONNECT command is
received.
Power ON
Phase 1 (Initial status)
Phase 2 (Asynchronous communications status)
Phase 3 (Synchronous communications status)
Connecting:
CONNECT command
(Asynchronous communications)
Set Synchronization
(SYNC_SET command)
Communications fault
Watchdog timer fault
Connecting:
CONNECT command
(Synchronous communications)
Disconnecting:
DISCONNECT command
Disconnecting:
DISCONNECT command