Model Explanation

B875 = 8-channel analog input series; 114 = 11-series PCB, hardware fixed 8-channel differential, factory locked 4-20mA, built-in standard 250Ω sampling resistor, no range jumper

111: Differential / Single-ended free switching, universal for full voltage current

114: Pure differential, only for 4-20mA current, no voltage acquisition circuit Technical Specifications

Channel Configuration: Fixed 8-channel differential input, cannot be changed to single-ended wiring. 250VAC isolation between channels, 300VAC insulation withstand voltage on the backplane.

Fixed Range: 4-20mADC dedicated, hardware cannot be connected to voltage signals. Built-in permanent 250Ω sampling resistor.

AD Accuracy: 12-bit analog-to-digital conversion, full-scale error ≤ ±0.11% FS at 25℃

Full Channel Scanning: Fixed refresh rate of 22ms

Backplane Power Supply: Rack 5VDC feed, rated 430mA, no need for external on-site power supply

Dimensions: 51 (W) × 203 (H) × 280 (D) mm, net weight 0.93kg

Status Indicators: RUN green for operation, OVER red for over-range, UNDER red for disconnected / below 4mA alarm

Environmental Parameters: Operation 0-60℃, Storage -40-85℃, humidity ≤ 80% RH without condensation, IP20 protection

Interface and Matching Base

Universal original screw terminal base: AS-8535-000, compatible with all B875 module bases.

Core Function

Specialized differential acquisition for long-distance strong interference conditions, compatible with two-wire 4-20mA pressure/temperature transmitters; UNDER light when circuit disconnected (<3.8mA), OVER over-range alarm when current > 21mA; Hardware has no jumpers or range jumpers, software can only configure 4-20mA range. Applicable scenarios

The measurement points of thermal power boilers, chemical reaction vessels, and long-distance wiring transmitters in water treatment systems, all on-site are 4-20mA instruments. The wiring distances are long and the industrial frequency interference is relatively large. The old Modicon 984 control system needs to be renovated and replaced.

Operation and Maintenance

Directly insert into the 800 rack I/O slot, the factory hardware is locked with differential + 4-20mA, and direct connection to voltage-type sensors is prohibited; UNDER alarm prioritizes troubleshooting of transducer power supply and circuit break; it can be mixed-inserted with the B875-100/101/102/111 series on the same rack.