Overview
ISO 22158:2011 - "Input/output protocols and electronic interfaces for water meters - Requirements" defines the minimum communication requirements for water meters that can exchange or provide data via an electronic interface. The standard specifies the electrical and electronic interface conditions at the meter terminals only; it does not mandate external equipment (for example transponders, inductive pads or reading devices). ISO 22158 is intended to ensure interoperable, repeatable interfaces between water meters and automatic or remote meter-reading systems.
Key technical topics and requirements
- Scope and types: The standard classifies meter interfaces into three types:
- Type A - Pulse output water meters (real‑time metering pulses)
- Type B - Non‑addressable water meters (data streams for coupling to a reader)
- Type C - Addressable water meters (bus/addressable communication)
- Pulse output definitions (Type A):
- Pulse output modes A1–A8, with defined pulse waveform characteristics and typical implementations (reed, transistor, optical, piezo, etc.)
- Data set types (e.g., O, U, B1, B2, N1, N2) describing omnidirectional, uni‑ and bidirectional pulse behaviours
- Signal output types: N (referenced to 0 V), P (referenced to positive supply), T (totem‑pole/push‑pull), W (floating)
- Pulse configuration, tamper‑detection options and marking conventions (example marking: “A1O”)
- Non‑addressable interfaces (Type B):
- Defined output modes B1–B3 and data set types (A, S1, S2) and common data protocols for encoded two‑wire/three‑wire interfaces
- Addressable interfaces (Type C):
- Output modes based on established technologies such as M‑bus, Dialog, and NABS (addressable 8‑bit electronic water meters)
- Normative references: The standard builds on related protocols and electrical standards (for example EN 13757, IEC 60870‑5, IEC 60947‑5‑6, M‑bus, NABS).
Practical applications and users
ISO 22158 is valuable for:
- Water meter manufacturers designing registers and electronic outputs to ensure compatibility with third‑party reading equipment
- AMR/AMI and telemetry integrators implementing automatic meter reading (AMR) or remote meter reading (RMR) systems
- Utilities and metering departments specifying meter procurement and interoperability requirements
- Test laboratories and conformity assessors verifying electrical and protocol compliance
- System designers integrating meters with transponders, inductive pads, bus nodes and data concentrators
Practical uses include enabling reliable pulse counting, encoded meter reading via inductive probes or direct bus connection, tamper detection signals, and integration into networked meter reading infrastructures.
Related standards (select)
- EN 13757 (communication systems for meters)
- IEC 60870‑5 series (transmission protocols)
- IEC 60947‑5‑6 (DC interface)
- M‑bus documentation and NABS specifications
Keywords: ISO 22158, water meter communication, electronic interfaces, pulse output, non‑addressable, addressable, M‑bus, AMR, remote meter reading, meter interoperability.