Hardware core specifications

Bus and serial port interface

LonWorks bus: Echelon Neuron chip, 78kbps differential twisted pair bus, connected to the entire Lon bus network

RS232 channel: 6 independent DB-9 RS232 serial ports, each with optoelectronic isolation and hardware flow control support; Connect to third-party serial peripherals such as RF matching devices, flow meters, spectral modules, temperature controllers, etc

Complete protocol encapsulation and unpacking within the board to alleviate the pressure on VME CPU serial port resources.

power supply

External 24VDC cabinet power supply, not powered from VME backplane

Onboard fuses, reverse polarity protection, ESD surge protection, protect serial ports from external device impacts.

Indicator lights and firmware

LED status lights: power supply, LonWorks bus communication status, 6-channel RS232 transceiver activity indicator lights

Onboard Flash storage node firmware, supporting Lon bus online firmware download and update.

Physics&Environment

Form: Independent PCB component, screw locked cabinet installation, not VME card insertion

Working temperature: 10 ℃ -50 ℃ (semiconductor cabinet environment)

Storage temperature: -20 ℃~+70 ℃

Origin: United States.

Main functions of the whole machine

Protocol gateway conversion: LonWorks ↔ 6-way RS232, enabling communication between the VME main control system and multiple serial peripherals without occupying scarce serial port resources in the VME chassis.

Serial port peripheral aggregation: Centralize the management of RF matching units, gas controllers, various process sub components with RS232 interfaces, and collect multiple serial port data for transmission on the Lon bus.

Local data frame buffering: Neuron chip performs frame caching and simple verification to reduce bus packet loss; The serial port fault is isolated independently, and a single RS232 short circuit will not paralyze other channels and Lon bus.

Fault reporting: Bus disconnection, single channel serial communication timeout, power supply abnormality throws node alarm to the upper computer.

Typical fault phenomena

Report LonWorks: The node is missing, and all 6 connected serial peripherals have lost communication

One of the process peripherals (RF matching/flow meter) reported an error during communication timeout, while the other 5 peripherals are working normally

Serial port data garbled, frame loss, incomplete reading of process parameters