From Scale to Shore: Weighing Data, IoT and System Integration

What weighing data integration means

Weighing data integration is the practice of moving every registered weight, with its context, from the scale into the systems that use it: label printers, catch registration, packing statistics, office software and shore-based sales, quota and traceability systems. The aim is that a weight is captured once, at the scale, and never retyped.

At sea this has specific constraints. Equipment is exposed to water, salt and vibration; networks run through steel structures; connectivity to shore comes and goes; and the crew has no time for data entry during a haul. At the same time, the demands on data are rising. EU traceability rules now require lot information, including net weight, to be passed on digitally, and buyers increasingly expect catch data before the vessel reaches port. A well-designed data chain turns these demands into a by-product of normal weighing.

The data chain from scale to shore

Every integration, however large or small, consists of the same five layers: measurement, local connection, onboard storage and applications, the ship-to-shore link, and shore systems.

Problems at a lower layer cannot be fixed higher up. A weight taken while the deck was moving, logged without a timestamp or sent without a unique ID will remain unreliable, however sophisticated the shore software. That is why integration starts at the scale.

What data to capture

Capture every weighing automatically with a unique record ID, UTC timestamp, instrument ID, preset or product, net weight with unit, stability status and the lot it belongs to; everything else is built on these fields.

Additional fields add value depending on the operation: tare and gross for verification, checkweigher result against target limits, species code and product form, position or catch area, operator and label reference. Alongside the weighing records, an audit trail should record calibration, setting changes, preset edits and software updates. OIML Document D 31 describes an audit trail as a continuous, time-stamped record of legally relevant events that may influence metrological characteristics (OIML D 31:2019).

From complete records, statistics per preset follow automatically: count, total, mean, standard deviation, minimum and maximum, and average giveaway. The full field list, conventions for time, units and decimal separators, and a comparison of export formats are in Weighing Data Logging at Sea: What to Record and Why.

Physical interfaces

The physical interface is chosen by distance, number of devices, environment and purpose: Ethernet for networked integration, RS232 for simple point-to-point links, USB for configuration and short local connections, and Wi-Fi or Bluetooth LE for portable devices.

Figures are drawn from Texas Instruments interface guidance, IEEE 802.3 and the USB 2.0 specification. Installation matters as much as the interface: sealed connectors, shielded cables routed away from winch motors and frequency drives, galvanic isolation between power circuits, and wireless coverage tested at the actual working position. The detailed comparison is in RS232, Ethernet, USB, Wi-Fi or Bluetooth LE: Choosing a Scale Interface.

Software integration and APIs

An API lets software read live weight, status, presets and stored records from a scale and send commands such as zero, tare and print, using structured data rather than parsing a display string.

Two integration patterns cover most needs. For live displays and interactive control on board, software polls the live weight frequently or receives pushed updates over a persistent connection. For everything that becomes a record, such as box weights, lot totals and anything sent ashore, software should read registered records from the scale's log, identified by record ID, rather than build its own records from polled live values. This avoids missed and duplicated weighings.

Remote commands need care: a tare sent at the wrong moment corrupts all following weighings. Check that the scale is stable before issuing commands, confirm the result, make retries harmless with request IDs, and separate read access from command rights. HTTP semantics are defined in RFC 9110 and JSON in RFC 8259. Endpoints, example payloads and the trade-offs between polling, WebSocket, Server-Sent Events and MQTT are explained in Integrating Scales with Your Software via an API.

Ship-to-shore data

Vessels send data ashore via mobile networks near the coast, L-band satellite services, geostationary VSAT or low Earth orbit broadband, and weighing data is small enough that any of these can carry it.

A day of 20,000 weighing records of about 250 bytes each amounts to roughly 5 MB, which a 352 kbps satellite uplink sends in about two minutes. Latency is not a concern for records that carry their own timestamps, although geostationary links add at least about half a second to every request and response because of the 35,786 km orbital altitude. The real design issue is intermittent connectivity: records must be stored on board first, queued, acknowledged by the shore side and de-duplicated by record ID. The options, a bandwidth table and a store-and-forward design are in Ship-to-Shore Data: Connectivity Options for Fishing Vessels.

Data formats and identifiers

Integration succeeds when both ends agree on formats and identifiers, so choose open, documented standards for files, time, species, lots and labels.

The regulatory drivers behind several of these identifiers are set out in Article 58 of the EU fisheries Control Regulation as amended by Regulation (EU) 2023/2842, which lists the minimum traceability information per lot, including the FAO alpha-3 species code, the geographical area, the gear category, catch dates and net weight in kilograms, and requires it to be made available digitally from 10 January 2026.

Linking weighing to catch registration and labelling

Weighing data becomes traceability data when each weight is linked to a lot, and it reaches the physical product when the same lot and weight are printed on the label.

In practice, the preset on the scale defines the product (species, presentation, target, tare, label template), the registration system supplies the lot and catch context (trip, area, gear, date), and the label printer receives the weight and lot at the moment of registration. When these three share identifiers, a box label, a log record and a traceability record always match. The processing side of this chain is described in the onboard processing hub, especially Catch Registration and Traceability from Haul to Harbour and Labelling Fish Boxes and Crates at Sea.

Reliability and security

A vessel data system must keep working without shore connectivity and must not open onboard equipment to the internet.

• Offline first. Every weighing is stored locally before any transmission. Losing the network must never mean losing records.
• Unique IDs everywhere. Record IDs make retries and re-imports safe.
• Clock discipline. Synchronise clocks with GPS or network time and log adjustments.
• Backups at port. Copy logs and configuration, including presets and label templates, at every port call.
• Network separation. Keep scales and graders on an operational network segment, separate from crew and guest traffic.
• Outbound connections only. Let an onboard gateway initiate encrypted connections to shore; do not expose scale interfaces directly.
• Access control. Restrict command and configuration rights, and change default credentials.

The IMO publishes guidelines on maritime cyber risk management that provide a framework for shipowners.

Example architectures

Three typical set-ups show how the layers combine at different scales of operation.

Inshore vessel, one scale

A motion-compensated bench scale logs every box weight internally. The skipper opens the scale's web interface from a tablet via its access point, checks totals per species, and exports a CSV file at port for the buyer. A label printer is connected directly to the scale. No permanent network or satellite link is needed.

Trawler with grading and registration

A grader and several scales are connected by Ethernet to a vessel PC running catch registration. Lots are created per species and haul; box labels with GS1 barcodes are printed at each packing station. Records are queued on the PC and sent ashore over 4G near the coast and satellite offshore, so the buyer receives lot data before landing.

Research vessel sampling station

Precision marine scales at a sampling station send each specimen weight to a data-entry application on a tablet or PC, together with length and station data, and export JSON to the institute's database after each cruise leg. Specific requirements for scientific work are covered on the research vessels hub.

How WPL approaches this

WPL builds the data chain into its marine weighing range. WeightControl runs directly on the R10 scale, needs no PC or server, and can be opened from a laptop or tablet browser via the scale's built-in access point; installed as an external application it manages several scales from one system. It logs every weighing, shows statistics per preset and period, exports PDF and CSV, and offers a JSON API for live weight, checkweigher status, stability, presets, logs and commands such as Zero, Print and Tare. The R10 Configuration Panel handles calibration, settings, presets, logs, backup and ZPL label design. Scales such as the M2 connect via USB, RS232 and Ethernet, with Bluetooth LE and the WeightControl IOT module as options, and the R50 Catch Label System can send catch data ashore during the trip.

Integration checklist

1. List every system that needs weighing data and the fields, formats and identifiers each expects.
2. Define presets per product, including target, tare and label template.
3. Choose interfaces per connection and plan cabling, connectors and wireless coverage.
4. Confirm that every weighing is logged locally with record ID, UTC timestamp, preset, net weight, unit, stability and lot.
5. Decide which data is read live and which is collected from logs.
6. Set up the ship-to-shore path with queueing, acknowledgement and de-duplication.
7. Separate the operational network, restrict command rights and change default passwords.
8. Test the full chain on board, including a deliberate loss of connectivity, before the first commercial trip.