ISO 11785:1996

Overview

ISO 11785:1996 specifies the technical concept for radio‑frequency identification (RFID) of animals. It defines how animal transponders are activated and how stored identification information is transferred to transceivers. ISO 11785 is intended to work together with ISO 11784 (code structure) and covers key system modes, signal formats, timing and conformance rules that enable interoperable animal identification systems.

Key topics and technical requirements

• Transmission modes: Supports both full‑duplex (FDX) and half‑duplex (HDX) transponder methods so a single transceiver can read either type.
• Activation frequency and timing: Transceivers use an activation field around 134.2 kHz with specified activation and pause periods (e.g., nominal 50 ms activation). Timing rules for mobile vs. stationary transceivers and activation/pause synchronization are defined.
• Signal formats:
  • FDX: Transponder transmits during activation using a modified differential bi‑phase (DBP) encoded sub‑carrier that is amplitude‑modulated onto the RF carrier.
  • HDX: Uses frequency‑shift keying (FSK) with two return frequencies (notably 124.2 kHz and 134.2 kHz), NRZ encoding and defined bit durations and bit rates.
• Identification telegram structure: Header, 64‑bit identification code (per ISO 11784), CRC error detection bits and a 24‑bit trailer; LSB first transmission order.
• Conformance: Transponders and transceivers must meet clause 6 requirements; Annex A provides rules for integrating legacy installed‑base technologies.
• Interoperability and legacy support: Annex A describes how to incorporate widely deployed systems (e.g., Destron, Datamars) into compliant transceivers to ease transition.
• Regulatory & IP notes: The standard draws attention to possible patent rights affecting implementations and notes that national radio approvals may be required.

Applications

ISO 11785 is the technical foundation for practical animal RFID uses, including:

• Livestock identification and traceability (cattle, sheep, pigs)
• Veterinary identification and health record linkage
• Biosecurity, animal movement control and regulatory compliance
• Breeding program management and farm automation
• Research tagging and wildlife monitoring (where compatible)

Who uses this standard

• RFID hardware manufacturers (transponders, readers)
• Agricultural equipment and animal‑ID system integrators
• Veterinary and livestock management solution providers
• Regulatory agencies and standards bodies specifying ID requirements
• Farmers, breeders and animal health organizations implementing traceability

Related standards

• ISO 11784:1996 - Code structure for RFID of animals (mandatory companion standard)

Keywords: ISO 11785, RFID animal identification, animal transponder, transceiver, FDX, HDX, 134.2 kHz, livestock traceability, ISO 11784.