ABB Advant Controller 450, Product Manual

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Advant Controller 450 Product Guide
Section 6.9 CPU Load Calculation
3BSE 015 953R201 Rev B 6-11
PI loop A simple analog control loop consisting of: 1 DB
element AI, 1 DB element AO, 1 PC element PI,
2 arithmetic and 3 logic PC elements 0.5
PID loop An advanced process control loop consisting of:
1 DB element AI, 1 DB element AO and 1 PID-
CON-loop. Arithmetic and logic PC elements 0.8
Adaptive PID
loop An advanced adaptive control loop consisting of:
1 DB element AI, 1 DB element AO and
1 PIDCONA-loop. Some arithmetic and logic
PC elements 1.0
PID loop
pulsed output 2 DB elements AI, 2 DB elements DO, 1 PIDCON
loop, 1 PC element CON-PU1 and Some arithmetic
and logic PC elements 1.0
Ratio station 1 DB element AI and 1 RATIOSTN 0.4
Motor control 1 1 DB element DO and 1 MOTCON 0.4
Motor control 2 1 DB element AI, 1 DB element DO, 1 MOTCON
and logic PC elements
0.7
(1) If digital inputs change frequently the load from interrupt-detected changes can be extensive. Each change takes
about 0.6 ms to handle. Example: If a DI changes its state once a second on the average, this will give rise to a
0.06% additional load per channel.
Table 6-10. Examples of CPU load
Description PC cycle time (ms) CPU load (%)
50 DI 50 2
500 DI 250 4
50 DO 50 2
500 DO 250 4
50 AI 1000 1
30 PIDCON 1000 2.5
30 PIDCONA 1000 3
10 PIDCON 2000 0.5
50 Motor controls 1 1000 2
50 Motor controls 2 1000 3.5
Table 6-9. Execution times (Continued)
Type Description
Execution time
(ms)