The most expensive part of buying a scale often comes afterwards
Two scales, same weighing range, 300 euros' price difference – the decision seems clear. Until three years later the values are supposed to go into the inventory-management system and it turns out: the cheaper one has no data output, or its protocol is documented nowhere. What follows is reverse engineering, an add-on module from the manufacturer, or a new scale altogether. So the interface question doesn't decide whether the scale weighs today – but whether it fits into your processes tomorrow.
Checklist before buying
- Which interface does the scale have? RS232, USB, Ethernet/TCP/IP or OPC UA – the main thing is that there is a data output at all. Which connection type fits when is explained in our guide Reading out a scale.
- Is the protocol documented? Explicitly ask for the interface description. An openly documented data protocol is worth more than any accessory package – it makes you independent of the manufacturer.
- Do you need legal-for-trade capability? If you bill by weight, you need a legal-for-trade-capable scale – and, for the software connection, ideally a terminal with an Alibi memory. Retrofitting is rarely possible.
- What does the future look like? Even if today it's only weighing and reading off: plan for the later connection to ERP, inventory management or quality assurance. The surcharge for a network-capable interface is small at purchase – retrofitting later is big.
- Several sites or workstations? Then go straight for Ethernet rather than a single serial connection – otherwise the scale is tied to exactly one PC forever.
Frequently asked questions
Besides accuracy, what should I look for when buying a scale?
Above all the data interface and its documentation. Clarify before buying: does the scale have RS232, USB, Ethernet or OPC UA? Is the data protocol openly documented by the manufacturer? Do you need legal-for-trade capability and therefore an Alibi memory? And should the scale later be connected to an ERP or inventory-management system? A cheap scale without a documented interface can cost more when it is later integrated than was saved at purchase.
Can any scale later be connected to an ERP system?
Not every one. The prerequisite is a data interface with a protocol that can be read out reliably – ideally documented by the manufacturer. Scales with no data output at all, or with proprietary, undocumented protocols, can only be integrated with great effort or not at all. Anyone who looks for an open, documented interface at purchase keeps the later connection to ERP, inventory management or quality assurance open at no extra cost.
Vendor-neutral purchasing advice as a service
Digital Trend Systems doesn't sell scales – which is precisely why we can advise you neutrally. If you're facing a purchase decision, we're happy to review your candidates' data sheets from a software perspective: interface, protocol documentation, integration capability. That way you buy the scale that still fits your systems in five years' time.
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