Zephyr Industrial Protocols

Build robust, industry-standard communication systems using Zephyr's modular industrial protocol stacks.

Core Workflows

1. Modbus RTU (Serial)

Implement serial-based industrial communication for meters, PLCs, and sensors.

• Reference: modbus_rtu.md
• Key Tools: CONFIG_MODBUS, RS-485 DE/RE handling, Register Mapping.

2. Modbus TCP

Bridge industrial data over standard Ethernet or Wi-Fi networks.

• Reference: modbus_tcp.md
• Key Tools: Port 502, TCP/IP networking, Client/Server patterns.

3. CANopen Basics

Integrate with complex automation networks using the CANopenNode stack.

• Reference: canopen_basics.md
• Key Tools: Object Dictionary (OD), PDO/SDO, Network Management (NMT).

Quick Start (Modbus RTU Server)

# prj.conf
CONFIG_MODBUS=y
CONFIG_MODBUS_SERIAL=y

// Initialize a server on a serial device
const struct device *dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_modbus_serial));
struct modbus_iface_param param = {
    .mode = MODBUS_MODE_RTU,
    .server = { .node_addr = 1, .cb = &my_callbacks },
    .serial = { .baud = 115200, .parity = UART_CFG_PARITY_NONE },
};
modbus_init_server(dev, param);

Professional Patterns (Reliability & Safety)

• RS-485 Hardware Handling: Always use the devicetree uart-rs485 property to handle transceiver direction signals automatically at the driver level.
• Isolated Communication: Use galvanically isolated transceivers for both serial and CAN lines in factory environments to prevent damage from ground loops.
• Watchdog Integration: In industrial control, always pair your communication loops with the watchdog_reliability pattern (see specialized skill) to ensure the system enters a fail-safe state on protocol lockup.

Automation Tools

• modbus_register_lint.py: Validate register map CSV files for duplicate addresses and overlaps.

Examples & Templates

• modbus_register_map_template.csv: Starter register allocation sheet for Modbus projects.

Validation Checklist

• Modbus RTU request/response exchange succeeds against a known test slave/master.
• Modbus TCP endpoint responds on port 502 with correct register mappings.
• CANopen node transitions through expected NMT states during startup.
• Communication faults trigger safe retry or watchdog-protected recovery behavior.

Resources

• References:
  • modbus_rtu.md: Serial Modbus master/slave setup.
  • modbus_tcp.md: Ethernet Modbus client/server patterns.
  • canopen_basics.md: Object Dictionary and PDO mapping.
• Scripts:
  • modbus_register_lint.py: Register-map consistency checker.
• Assets:
  • modbus_register_map_template.csv: Register planning template.