• “ADV” = Product series identifier, representing “Advanced Signal Processing” — emphasizing enhanced precision and multi-signal compatibility, differentiated from basic “ASC” series conditioning modules.
• “551” = Model sequence code: “5” denotes the mid-range industrial signal module family; “51” specifies 4-channel analog input + signal conversion functionality (distinguished from “61” series with output capabilities).
• Core positioning: Serves as a “signal optimization hub” for industrial process control systems (e.g., DCS, PLC-based monitoring systems), adapting to temperature, pressure, and flow sensor signals in industries like chemical, oil & gas, and water treatment.)

2. Product Description

1. 4-Channel Universal Signal CompatibilityIntegrates 4 independent analog input channels, each supporting mainstream industrial signals: 4-20mA DC (current loop, compatible with 2-wire/4-wire transmitters), 0-10V DC (voltage signals from level sensors), and Pt100/Cu50 RTDs (for temperature measurement). Each channel can be independently configured via DIP switches or software (signal type, gain, filtering level) — enabling mixed-signal monitoring (e.g., 2 channels for Pt100 temperature, 1 for 4-20mA pressure, 1 for 0-10V flow) without hardware replacement, reducing system redundancy by 35%.
2. High-Precision Signal ConditioningAdopts a 16-bit high-performance ADC chip, achieving an acquisition accuracy of ±0.1% FS (at 25°C) and a temperature measurement error of ≤±0.2°C (for Pt100 signals) — meeting strict requirements for critical processes (e.g., pharmaceutical fermentation temperature control with ±0.3°C tolerance). Built-in dual anti-interference mechanisms:
3. • Hardware: Differential input design + 50/60Hz notch filtering, suppressing power grid harmonics and motor electromagnetic interference (EMI).
   • Software: Cold-junction compensation (for thermocouples, if extended) and linearization correction, minimizing signal distortion caused by environmental factors. Signal fluctuation is controlled within ≤±0.05% FS.
4. Flexible System IntegrationSupports two communication interfaces for seamless connection to control systems:
   • RS485 (Modbus-RTU protocol): Baud rate 9600–115200bps, maximum transmission distance 1200m, compatible with PLCs (e.g., Siemens S7-1200, Allen-Bradley Micro800) and SCADA software (e.g., Wonderware Intouch).
   • Analog output (optional): 4-20mA DC/0-10V DC, directly connecting to DCS analog input cards (e.g., Yokogawa P0926KL) for legacy system upgrade.

     It also supports online calibration via software, eliminating on-site disassembly and improving maintenance efficiency by 60%.

5. Rugged Industrial DurabilityConstructed with a flame-retardant ABS enclosure (UL94 V-0 rating) and conformal-coated PCB (moisture, corrosion, and mold resistance), achieving an IP20 protection rating (suitable for cabinet-mounted installation). It operates reliably in a temperature range of -20°C~+70°C and tolerates 5%~95% non-con