ABB 07 EA 81 Analog Input Module

Technical Specifications and Module Design

This analog input module interfaces with field sensors for ABB Procontic systems. The ABB 07 EA 81 converts voltage and current signals into digital values for the CPU. You can install this module into any standard Procontic rack slot position. Its high-precision circuits provide accurate measurement in industrial environments. The module weighs approximately 0.65 kilograms. Its dimensions measure 27 cm in height, 23 cm in width, and 21 cm in depth.

Parameter	Specification
Brand	ABB
Model	07 EA 81
Category	Analog Input Module / Signal Converter
Weight	0.65 kg
Height	27 cm
Width	23 cm
Depth	21 cm
Number of Inputs	8 differential channels
Input Voltage Range	±10V DC (selectable)
Input Current Range	0-20 mA or 4-20 mA (selectable)
Input Impedance	100 kΩ (voltage), 250 Ω (current)
Resolution	14-bit (0.0012V or 0.0012 mA)
Accuracy	±0.1% of full scale at 25°C
Conversion Time	5 milliseconds per channel
Common Mode Rejection	80 dB at 50/60 Hz
Isolation Voltage	1500V AC between channels and logic
Energy Storage	None (no battery)
Component Count	Single PCB with ADCs, amplifiers, and optocouplers

Signal Processing and Input Conditioning

Each channel accepts either voltage or current signals independently. You can select the input type using an onboard DIP switch per channel. The ABB 07 EA 81 provides programmable gain amplification for low-level signals. Built-in anti-aliasing filters remove high-frequency noise from input signals. The module converts all eight channels sequentially with automatic channel scanning. A green LED indicates when each channel is active during scanning. The inputs tolerate overvoltage up to ±30V without damage.

Wiring and Group Isolation

The module divides its eight inputs into two isolated groups of four. Each group has its own common reference terminal for ground separation. You can connect different signal sources to each group safely. The ABB 07 EA 81 uses a front-panel screw terminal strip for field wiring. This terminal strip accepts wire sizes from 0.2 to 2.5 square millimeters. The module provides 1500V isolation between input channels and the backplane. Consequently, ground loops will not affect measurement accuracy. Each input includes overvoltage protection up to 220V AC.

Installation and Operational Guidelines

You must insert this module into any standard Procontic rack slot position. The backplane supplies 5V and ±15V DC power to the module automatically. The ABB 07 EA 81 draws approximately 250 mA from the 5V supply rail. You must use shielded twisted-pair cables for all analog input connections. This practice prevents electrical noise from corrupting low-level signals. The module stores no configuration data independently. Therefore, the CPU retains all scaling and calibration values. The operating temperature ranges from 0°C to 55°C.