Schneider ASB873001 Analog Input Module

The Schneider ASB873001 converts eight analog sensor signals into digital values for Modicon PLCs. This input module accepts 0-10 VDC signals from pressure and temperature transmitters. You will find it in process control systems across many industries. It delivers 12-bit resolution for accurate measurement of physical parameters. Therefore, this unit suits chemical, pharmaceutical, and water treatment facilities.

This module measures 130 mm in height and 45 mm in width. Its depth reaches 100 mm for standard rack mounting. The unit weighs approximately 0.39 kilograms. It contains one 12-bit ADC with multiplexed inputs. Four isolation barriers separate field circuits from the backplane. Additionally, you get eight status LEDs for channel monitoring.

Key Technical Specifications

Parameter	Value
Manufacturer	Schneider Electric (Telemecanique)
Model	ASB873001
Product Type	Analog Input Module
Number of Channels	8 (single-ended)
Input Signal Range	0-10 VDC
ADC Resolution	12 bits (4096 steps)
Accuracy	±0.5% of full scale
Input Impedance	100 k ohms
Conversion Time	2 ms per channel
Channel Isolation	1500 VAC (optical)
Height	130 mm
Width	45 mm
Depth	100 mm
Weight	0.39 kg
ADC Count	1 (multiplexed)
Isolation Barriers	4 (optical)
Status LEDs	8 (yellow)
Energy Storage	≈ 220 µF (capacitive)
Power Consumption	190 mA @ 5 VDC
Operating Temperature	0°C to +55°C
Terminal Type	Removable screw block

Internal Architecture and Energy Storage

The Schneider ASB873001 stores minimal energy in its input filter circuits. Small electrolytic capacitors hold approximately 220 microfarads total capacitance. A single 12-bit ADC multiplexes through all eight input channels sequentially. This ADC converts each analog value in just 2 milliseconds. Four optical isolators protect the backplane from field wiring noise. Each input channel has a programmable gain amplifier for signal conditioning. The module includes a precision voltage reference at 2.5 VDC. An 8-to-1 analog multiplexer routes each channel to the ADC input. A microprocessor manages the conversion sequence and data formatting.

Connection Interfaces and Wiring Details

You will find a 20-pin removable terminal block on the bottom face. This block accepts eight analog input pairs plus shield connections. Connect the positive signal wire to the channel terminal. Connect the negative return wire to the adjacent common terminal. Use shielded twisted-pair cable for all analog signal runs. Connect the shield drain wire to the ground terminal only. The Schneider ASB873001 requires no external power supply for sensors. The module draws all necessary power from the 5 VDC backplane rail. Eight yellow LEDs light up when their respective channel receives a valid signal.

Configuration and Installation Steps

You slide this module into any I/O slot of the Modicon rack. First, align the module with the upper and lower card guides. Then, push it firmly until the backplane connector seats completely. Secure the front panel with the two retaining screws. Connect all field wiring before applying power to the system. The Schneider ASB873001 requires no jumpers or dip switch settings. Use the PLC programming software to read the input registers. Map each analog channel to a %IW memory address. The module automatically scales 0-10 VDC to 0-4095 digital counts. Test each channel with a voltage calibrator before connecting field sensors.