AiVibeAnalogue I/O
Analogue I/O are controller channels that convert continuously varying signals, such as 4–20 mA or 0–10 V from transmitters, into digital values for the PLC, and convert digital values back into signals that position valves or set drive speeds.
An analogue input module samples a current, voltage, resistance or thermocouple signal and converts it with an analogue-to-digital converter into an integer or engineering value. Resolution, expressed in bits, sets the smallest change the module can distinguish, while accuracy, conversion time and filtering determine how faithfully it represents the process. Analogue outputs work in reverse, using digital-to-analogue converters to drive standard current or voltage signals to actuators.
Analogue signals carry measurements of pressure, flow, level, temperature, weight and speed, and commands to control valves, dampers and variable frequency drives. They are the backbone of process control and closed-loop PID regulation, in which the controller compares a measured value with a setpoint and adjusts an analogue output.
Engineers must scale raw counts to engineering units, choose between current and voltage signals, and decide on single-ended or differential inputs and channel-to-channel isolation. Current signals tolerate long cable runs and electrical noise better than voltage signals. Shielded twisted-pair cable, correct grounding, wire-break detection and out-of-range diagnostics improve reliability. Digital protocols such as HART, IO-Link and fieldbuses can carry measurements alongside or instead of analogue signals.
Key points
- Convert continuous signals such as 4–20 mA and 0–10 V to and from digital values
- Resolution in bits sets the smallest distinguishable change
- Raw counts must be scaled to engineering units in the controller
- Current loops resist noise and long cable runs better than voltage signals
- Essential for process measurements and PID-controlled actuators
Where AiVibe comes in
AiVibe designs and manufactures the AiAmbA AI Factory, whose edge devices and AI agents let people talk to PLC, CNC and robot controllers in plain language. Agents only propose changes, a trained operator confirms each one, and the AI Factory never replaces a machine's control or safety systems.
Related terms
- 4–20 mA Current LoopPLC & Industrial Control
- Discrete I/O (Digital Inputs and Outputs)PLC & Industrial Control
- PID ControllerPLC & Industrial Control
- HART ProtocolPLC & Industrial Control
- Remote I/O (Distributed I/O)PLC & Industrial Control