9
PROCESSING TIME FOR REDUNDANT SYSTEMS
9.1 Extension of Scan Time due to Tracking
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9.1 Extension of Scan Time due to Tracking
Refer to Table9.1 for the calculation of extended scan time of control system CPU module
due to tracking.
Table9.1 Extension of Scam Time due to Tracking
Tracking Mode
Scan Time Extension Time (ms)
Synchronized Tracking
Mode
Ts = Tra + Trb +
Program
Priority
Mode
Tp >= Trb
Ts = Tra +
Tp < Trb
Ts = Tra + Trb - Tp +
Ts: Scan Time Extension Time
Tra: Tracking Data Preparation Time
Trb: Tracking Processing Time
Tp: Program Execution Time
: Overhead time for tracking transfer
(according to the right table)
Condition
(ms)
Both systems are normal
Max. 4
When a momentary power failure or
power-off occurs in the standby system
Momentary power
failure time to max.
40
While communication is executed via
tracking cable
Max. 30
Control system
Standby system
Extension of Scam Time
Sequence
Sequence
Adjust Tracking transfer data
Tra
Trb
0
Tracking transfer process
END
Control system
Standby system
Extension of Scam Time
Sequence
Sequence
Adjust Tracking transfer data
Tra
Trb
0
0
Tra
Tracking transfer process
END
Control system
Standby system
Extension of Scam Time
Sequence
Sequence
Adjust Tracking transfer data
Tra
Trb
0
Tra
Tracking transfer process
END