Wago 750-668/000-004 FS 4AI 0/4-20mA Yellow

Why Choose the WAGO 750-668/000-004 PROFIsafe Fail-Safe Analog Input Module?

The WAGO 750-668/000-004 is a fail-safe 4-channel analog input module designed for safety-critical automation systems within the WAGO I/O System 750. It enables safety-related process signals to be integrated into PLC-based control systems using the PROFIsafe safety protocol, ensuring secure transmission of analogue measurement data in functional safety applications.

The module provides four differential analog inputs supporting measurement ranges of 0…20 mA and 4…20 mA. Each input channel includes comprehensive safety monitoring functions such as wire-break detection, overload detection and configurable discrepancy monitoring for dual-channel safety applications. :contentReference

Designed for safety automation systems, the module can operate in either single-channel or dual-channel safety configurations. Dual-channel operation enables functional safety levels up to SIL 3 / Category 4 / Performance Level e, making the module suitable for high-integrity industrial safety systems. :contentReference

Key Advantages

• Fail-safe 4-channel analog input module for safety automation.
• Supports 0…20 mA and 4…20 mA process signals.
• Compatible with PROFIsafe safety communication.
• Continuous monitoring for wire break, overload and signal faults.
• Supports SIL 3 / Category 4 / PL e in dual-channel applications.
• Compact DIN rail module for WAGO I/O System 750 installations.

Key Features

• 4 differential fail-safe analog inputs.
• Measurement range: 0…20 mA or 4…20 mA.
• Integrated sensor supply outputs for connected devices.
• Configurable measurement filters and sampling cycle.
• Adjustable discrepancy monitoring for dual-channel safety.
• Parameterisation using WAGO engineering tools.
• Automatic parameter download from controller via PROFIsafe iPar server.
• Status LEDs for module and channel diagnostics.

Technical Specifications

• Manufacturer: WAGO
• Series: I/O System 750
• Model: 750-668/000-004
• Module type: Fail-safe analog input module
• Number of inputs: 4 differential analog inputs
• Input ranges: 0…20 mA / 4…20 mA
• Signal type: Differential current input
• Safety protocol: PROFIsafe (V2.4 / V2.6)
• Safety levels: up to SIL 3 / Category 4 / PL e
• Sensor supply outputs: 4 current-limited outputs
• System supply voltage: 5 V DC via internal system bus
• Field supply voltage: 24 V DC
• Connection technology: WAGO CAGE CLAMP® spring terminals
• Mounting: DIN-35 rail
• Operating temperature: 0 to 55 °C
• Dimensions: approx. 24 mm width
• Protection rating: IP20

Safety Monitoring for Process Signals

In safety-critical automation systems, analogue process signals from sensors such as pressure transmitters, flow sensors and level transmitters must be monitored reliably. Fail-safe analogue input modules ensure these signals are transmitted securely and continuously checked for faults.

The WAGO 750-668/000-004 integrates analogue safety monitoring into the distributed WAGO I/O architecture. With PROFIsafe communication and advanced diagnostics, it enables safety PLCs to monitor process conditions and trigger protective actions when abnormal values are detected. :contentReference

Typical Applications

• Process safety instrumentation systems.
• Monitoring pressure, flow and level sensors in safety circuits.
• Safety-rated process control in chemical and energy industries.
• Distributed safety monitoring networks.
• Machine and process automation safety systems.

Trusted by Automation Engineers

WAGO safety I/O modules are widely deployed in process automation and machine safety systems where reliable acquisition of analogue safety signals is essential for functional safety compliance.