ABB Advant Controller 450 User Manual

Advant
®
Controller 450 User’s Guide
Chapter 4 Runtime Operation
4-26 3BSE 002 415R701 Rev A
you can select interrupt-controlled scanning of digital inputs by selecting the parameter SCANT
to INTERRUPT. You can select different values of SCANT in the range 10 ms to 600 s.
See the reference manual Data Base Element for available standard scanning times.
Inputs scanned at intervals of 10 ms - 2 s are scanned under the corresponding PC interpreter to
obtain close synchronization between scanning and PC execution. The synchronization
functions if the scanning time and the cycle time for the PC belong to the same interpreter.
There is no scanning if the PC program is not dimensioned. Scanning of inputs with the
standard times 5 - 600 s is not synchronized.
4.1.11 Data Transport
4.1.11.1 Reading-in Phase
Each execution of an execution unit begins with a reading-in phase. This means that all PC
elements in the execution unit have input data which is read on the same occasion. The weight
of associated data during the complete execution is illustrated with the example in Figure 4-18.
Assume that execution of element .20 is followed by an interrupt caused by the digital input
signal changing status from 1 to 0. When the execution is resumed with element .21, the signals
MOTOR ON and MOTOR OFF are active simultaneously. The system automatically introduces
a reading-in element (an “invisible” GET element) which reads the values of the input signals at
the beginning of the execution of the unit and stores them in the local data area to prevent such
faults.
Figure 4-18. Example of Reading-in Phase
CONTRM
(50ms)
.20
.21
S
R
S
R
MOTOR ON
MOTOR OFF
Digital input
board
ON
OFF

ABB Advant Controller 450 Specifications

General

Brand	ABB
Model	Advant Controller 450
Category	Controller
Language	English