ProSoft Technology PTQ-104C - Manual (Page 83)

49TPTQ-104C ♦ 48TQuantum Platform Hot Standby Support
47TIEC 60870-5-104 Client
12TUser Manual
7.1.2 Primary and Standby Controllers
The Primary controller executes the application program, controls the remote I/O,
and updates the Standby controller after every scan (program cycle). If the
Primary controller fails, the Standby controller takes control within one scan. To
determine if the Primary controller failed note controller’s status displayed in the
HE CPU LCD screen and the RIO Head’s status displayed by the RIO Head’s
LEDs.
The Standby controller does not execute the full application program but only the
first section, and the Standby controller does not control the remote I/O but
checks out the availability of the Modicon Quantum Hot Standby with Unity
equipment.
Note: For additional information on Quantum Hot Standby support, refer to the Unity Pro Hot
Standby User Guide.
ProSoft Technology, Inc. Page 83 of 136
March 4, 2013