Calculadora de Temporización del Bus CAN
Calcula los parámetros de temporización del bus CAN: prescaler, segmentos de bit y velocidad de baudios.
Fórmula
tq = 1/(f_clk/BRP); NBT = SS + PROP + BS1 + BS2
Cómo Funciona
CAN (Controller Area Network) Bus bit timing is a critical parameter in designing communication protocols for automotive and industrial networks. It determines how data is transmitted and interpreted across the network by defining the relationship between bit time, sampling point, and synchronization segments. The bit timing configuration involves key parameters like bit rate, clock frequency, and propagation delays that impact signal integrity and network performance.
Ejemplo Resuelto
Consider a CAN Bus system with a 500 kbps bit rate and an 80 MHz system clock. Calculate the bit time and segment proportions: 1. Bit Time = 1 / (Bit Rate) = 1 / 500,000 = 2 µs 2. Time Quantum = 1 / (System Clock) = 1 / 80,000,000 = 0.0125 µs 3. Total Time Quanta = Bit Time / Time Quantum = 2 µs / 0.0125 µs = 160 time quanta 4. Typical Segment Distribution: Sync (1 TQ), Prop (2-8 TQ), Phase1 (1-8 TQ), Phase2 (1-8 TQ)
Consejos Prácticos
- ✓Always consider network length and bus characteristics when setting bit timing
- ✓Ensure sampling point is around 80% of bit time for optimal signal detection
- ✓Use minimal propagation delay segments for high-speed networks
- ✓Match bit timing across all network nodes for consistent communication
Errores Comunes
- ✗Mismatching bit timing parameters between network nodes
- ✗Neglecting cable length and signal propagation delays
- ✗Overlooking system clock precision and potential jitter
Preguntas Frecuentes
What is the typical CAN Bus bit rate?
CAN Bus supports bit rates from 10 kbps to 1 Mbps, with 250 kbps and 500 kbps being most common in automotive applications.
How do time quanta relate to bit timing?
Time quanta are the smallest time unit used to divide and configure CAN Bus bit segments, allowing precise timing control.
Why is sampling point important in CAN Bus?
The sampling point determines when the bus signal level is measured, which is crucial for reliable data interpretation and noise immunity.
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