Description
Alstom ALP121-S00
Technical Specifications Multi galvanically isolated analog input channels; support 4-20mA current signal input; 16-bit analog-to-digital conversion; measurement accuracy ±0.15% full scale; isolation voltage 1500V AC between field side and rack bus; 24V DC power supply; operating temperature -20°C to +70°C; IP20 protection grade.
Functional Features Receive analog current signals from pressure, temperature, flow and liquid level transmitters in power plants. Filter high-frequency interference signals superimposed on field loops. Convert conditioned analog signals into digital engineering values according to channel scaling parameters. Detect open circuit and short circuit faults of each signal loop and report alarm information to the main controller. Transmit measurement data and channel diagnostic status to the rack backplane bus. Provide surge overvoltage protection for field wiring terminals.
Application Scenarios Power boiler temperature and pressure monitoring, turbine auxiliary oil system measurement, hydropower station water level and flow monitoring, substation cooling system analog signal collection, generator auxiliary parameter monitoring.
Performance Parameters Low long-term signal drift; strong suppression of power frequency interference; stable sampling rate for closed-loop regulation; fast fault diagnosis response for field signal loops.
Material Composition Main PCB is FR-4 flame-retardant multilayer printed circuit board; analog conversion and signal conditioning chips are industrial semiconductors; optocoupler components realize channel galvanic isolation; backplane gold fingers adopt gold-plated copper alloy; housing is flame-retardant thermoplastic; terminal spring pieces use nickel-plated copper alloy.
Structural Characteristics Vertical plug-in rack module compatible with Alstom control rack. Front panel carries power, communication and channel fault LED indicators. Rear gold finger connector connects to rack backplane for power and bus data transmission. Front screw terminal blocks are used for field transmitter wiring. Side buckle locks the module in the slot.
Working Principle Field 4-20mA analog signals enter the channel signal conditioning and isolation circuit. After filtering and voltage conversion, the signal is sent to the analog-to-digital converter to generate digital raw values. The onboard processor applies preset scaling formulas to convert raw data into readable engineering values, and upload measurement results and fault status to the main logic module through the backplane bus.
Installation Requirements Cut off rack power before module installation or replacement. Insert the module into the specified rack slot and lock the buckle. Use shielded twisted-pair cables to connect field transmitters to module terminals. Set signal range and scaling parameters in supporting engineering software. Conduct loop signal test and channel calibration after power is restored.
Precautions for Use Adopt single-point grounding mode for cable shielding layer. Avoid laying analog signal cables in parallel with high-current power cables. Do not apply voltage exceeding the rated isolation value to field terminals. Back up system configuration before module replacement.
