5 Questions to Ask About an Analyzer's Interface Before You Buy

Integration has quietly become a purchase criterion for chemistry and immunoassay analyzers. Brochures now mention "LIS connectivity" next to throughput and reagent capacity. What they almost never publish is the checklist that tells you whether that connectivity will actually work in your lab.

This guide is that checklist. Five questions, in the order we would ask them, each with what a good answer looks like. Ask them before the purchase order, and ask for the answers in writing.

Question 1: What Dialect, Exactly, and Which Version?

"Supports HL7" is not an answer. HL7 version 2 has many versions and many local variations, and ASTM E1394 has its own. Ask for the exact dialect and version: for example, HL7 v2.3.1 ORU^R01 for results. Then ask the follow-up that matters: does the analyzer follow the standard as written, or does it deviate?

Real analyzers sometimes omit a field, add a framing byte, or use a format that is neither standard. We went through three real examples in our post on analyzers that speak neither HL7 nor ASTM. A vendor who knows the answer will tell you the quirks. A vendor who does not will repeat the brochure.

Question 2: Which Direction: Results Only, or Orders Too?

Some analyzers only send results out. Others can also receive test orders from the LIS. The difference is large in daily work. A results-only analyzer needs someone to enter the worklist at the instrument. A bidirectional one gets the orders automatically, which removes a manual step and a source of mismatches.

Ask directly: can the analyzer receive orders from the LIS, and in which message format? Of the 37 instruments LISBridge supports, 17 are bidirectional. Our post on bidirectional lab orders explains what that changes.

Question 3: What Transport: Serial, TCP, or a File Server?

Three different connection types are in use, and they are three different problems.

• RS-232 serial. Common on older and smaller instruments. It needs a correct cable and matching settings.
• TCP/IP. A network connection, with the question of which side listens and which side connects.
• File server. Some analyzers exchange XML files over FTP, FTPS or SFTP rather than holding a connection.

Ask which one the model uses, whether more than one is available, and whether a cable or adapter ships in the box. See how we handle each on the device connectivity page.

Question 4: Does It Wait to Be Asked?

Analyzers differ in who starts the conversation. A push analyzer sends results when they are ready and does not care who is listening. A host-query analyzer reads a sample barcode and then asks the LIS what to run, usually allowing only a few seconds for a reply.

That second type changes what your integration has to do. The software on the other end must answer fast, and must have a sensible response when the sample has no order. Ask whether the analyzer uses host query, how long its reply window is, and what it does when the window closes with no answer. Our explanation of host-query worklists covers the mechanics.

Question 5: What Happens When the Link Drops Mid-Send?

Cables get unplugged, switches reboot, and PCs restart. The question is what happens to a result that was in flight. Does the analyzer queue it and resend? Does it discard it? Does it retry forever and flood the receiver when the link returns?

Then ask the same question of the software side. LISBridge reconnects automatically with exponential backoff and jitter, and stores results in crash-safe local storage, so a power cut or restart does not lose data. A good answer from any vendor names the behaviour. A weak answer says "it should be fine".

How to Get the Answers in Writing

1. Send the five questions as an email to the analyzer vendor's applications team, naming the exact model.
2. Ask for the host-connection or interface specification document for that model.
3. Ask for a sample capture of a result message, if they have one.
4. Put the answers into the purchase paperwork, or at least keep them on file.

What a Pre-Built Parser Changes

If your middleware already has a parser for the model, most of these questions are answered before you ask them. The dialect, the quirks, the direction, and the transport are already handled. You can check the instrument directory for your model, and the pricing page shows how plans scale with your lab. If the model you are considering is not on the list, that is worth knowing before you buy.

A Short Scoring Sheet You Can Reuse

When you compare two or three candidate analyzers, put the five answers side by side. For each model, record the dialect and version, whether it takes orders, its transport, whether it uses host query, and what it does when the link drops. Mark each answer as documented, told verbally, or unknown. Unknowns are not automatically disqualifying, but they are risks you should price into the decision.

A useful rule is that two or more unknowns on the same analyzer justify a trial before purchase, or at least a request for a sample capture. The cost of asking is a few emails. The cost of discovering a mismatch after installation is weeks of engineering time and a lab running on manual entry in the meantime.

Why Manual Entry Is the Real Comparison

It helps to remember what you are comparing against. For many labs the alternative to a working interface is a technician reading a result off a screen and typing it into the LIS. In a hospital with five analyzers, that adds up to about two hours a day of transcription, and every typed value is a chance for an error. After automated connection, data accuracy is above 99.9%. The five questions above are really a way of making sure the interface you are buying will get you there, rather than leaving you with a connected cable and a manual process.

Questions That Belong to the Middleware, Not the Analyzer

Once you have the analyzer's answers, the same questions apply to the software that will talk to it. Does it have a parser for this exact model? Does it work offline? Can you see the raw data? Our guide to choosing lab middleware picks up where this checklist ends.

Frequently Asked Questions

Should I ask these questions even if the analyzer says it supports HL7?

Yes. HL7 support varies by version and by vendor deviation, and it says nothing about direction or transport.

Do I need a bidirectional analyzer?

Not always, but it removes manual worklist entry. If your volume is high or your error tolerance low, it is worth asking for.

Can I test an interface before buying the analyzer?

Often you can test the middleware side with a trial, and ask the vendor for a sample capture of the analyzer's output.

What is a host-query analyzer?

One that asks the LIS what tests are ordered after it reads a sample barcode, rather than waiting for a worklist.

How many analyzers does LISBridge support?

37 instruments out of the box, 17 of them bidirectional.

Start your free trial — no credit card required. lisbridge.com/pricing