If you're connecting a point-of-care analyser, you'll meet three acronyms quickly: HL7, POCT-1A and ASTM. They overlap, they're often confused, and the device manual rarely explains the difference. Here's the plain version.
ASTM — the original wire format
ASTM (specifically ASTM E1381 for the low-level transport and E1394 for the message content) is one of the oldest standards for laboratory-instrument communication. It defines how an analyser frames and sends records of patients, orders and results, classically over a serial connection. A lot of established benchtop instruments still speak it, often bridged onto a network.
HL7 — the language of health systems
HL7 v2 is the messaging standard that hospital and clinic systems use to talk to each other. For diagnostics, the two messages that matter most are ORU (an observation/result going out) and ORM (an order coming in). HL7 isn't device-specific — it's the broader lingua franca, typically carried over MLLP (a thin framing layer on TCP). If you want results to flow into a LIS or EHR, you'll almost certainly be speaking HL7 at some point in the chain.
POCT-1A — built for the point of care
POCT-1A (and its revision POCT-1A2) is the standard designed specifically for point-of-care connectivity. It defines how a point-of-care device, an access point, and a data manager exchange observations and directives — including device status, operator and reagent information, and crucially, instructions sent back to the device. It's the standard that anticipates the realities of distributed, near-patient testing rather than a central lab bench.
How they fit together
A common pattern in a connected clinic: analysers speak POCT-1A or ASTM (or a vendor frame) to a local connectivity layer; that layer normalises everything and then speaks HL7 outward to the LIS, EHR or reporting system. You don't usually pick one and abandon the others — you translate between them. The software doing that translation is what the industry calls POCT middleware.
A quick way to tell which your analyser speaks
- Look in the device's connectivity / communication settings menu — the protocol is often named there.
- Check the interface specification in the device manual (sometimes a separate "LIS" or "host" manual).
- If it offers an IP address and port, it's network-capable; the framing is usually HL7/MLLP, POCT-1A, or ASTM-over-TCP.
- A capable connectivity platform can auto-detect the wire format on first connection, so you don't have to be certain in advance.
How Catenix handles all three
Catenix supports HL7, POCT-1A and ASTM (plus selected proprietary frames), translating each into one normalised stream and — where the standard allows — talking back to the device. See Devices & integrations for the full picture, or read What is POCT connectivity? for the bigger context. If you're weighing platforms against each other, start with our POCT middleware comparison framework.
Questions, answered
The two questions that come up every time.
Which is better, HL7 or POCT-1A?
Neither is universally better — they solve different problems. POCT-1A is purpose-built for point-of-care device connectivity, while HL7 v2 is the broad messaging standard used across hospital systems. Many point-of-care setups use both.
How do I know which protocol my analyser uses?
Check the device's interface or connectivity manual, or its network/communication settings menu. Many analysers support more than one protocol; some auto-negotiate. A connectivity platform can also detect the wire format on first connection.