ABB Advant Controller 450 - Estimated Application Functions

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Use the following execution times and load figures when the shortcut method of CPU load
calculation is applied:
• One feedback control loop takes approximately 0.8 ms.
Thirty feedback control loops with the cycle time 1000 ms thus give approximately 2.5%
load. (Complexity: 1- PIDCON, 1- AI, 1- AO and several calculation and logic elements.)
• A corresponding feedback control loop as above but using PIDCONA takes approximately
1.0 ms.
• One feedback control loop for a three-position actuator takes approximately 1.0 ms.
Ten such loops with the cycle time 2000 ms give approximately 0.5% load.
Complexity: 1- PIDCON, 1- CON-PU1, 2- AI, 2- DO and some calculation and logic
elements.
• When cascade-coupled regulators are applied, consider approximately each loop in the
cascade as a single loop. Use the figures above.
• A simple feedback control loop takes approximately 0.5 ms.
Complexity: 1- PI element, 1- AI, 1- AO and 5 simple arithmetic and/or logic elements.
• One ratio station or manual station takes approximately 0.5 ms.
Complexity: 1- RATIOSTN alt. MANSTN, 1- AI, some arithmetic and logic elements.
• One AI or AO takes approximately 0.25 ms.
The load figure is valid to different AI signal types: standard signal, Pt 100 and
thermocouple signal.
Fifty AI with cycle time 1000 ms gives approximately 1% load.
Complexity: 1- AI alt. 1- AO.
• One measuring circuit, for example mass flow measuring, max/min selector, application
adapted linearization, and so on takes approximately 0.4 ms.
Complexity: 1- AI, some 5 arithmetic elements and logic elements.
• A motor drive takes approximately 0.7 ms.
Fifty motor drives with cycle time 1000 ms give approximately 3.5% load.
Complexity: 1- MOTCON, 1-AI, 5- DI (interrupt), 1- DO, some logic elements.
• An on/off valve control takes approximately 0.3 ms.
Fifty valve controls with cycle time 1000 ms give approximately 1.5% load.
Complexity: 1- VALVECON, 2- DI, 1- DO, some logic elements.
The execution time of a digital signal DI or DO with attached interlocking logic depends of
certain conditions. Table 3-12 gives you some alternative applications.