HL7 EAC_U07 (Automated Equipment Command) | Integration Soup HL7 Reference Guide

HL7 EAC_U07 Automated Equipment Command

A controlled way to tell lab automation equipment what to do next.

HL7 message structure EAC_U07 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

Segment	Name	Required	Repeatable
MSH	Message Header	Yes	No
SFT	Software Segment	No	Yes
EQU	Equipment Detail	Yes	No
EAC_U07.COMMAND	Command group	Yes	Yes
ECD	Equipment Command	Yes	No
TQ1	Timing/Quantity	No	No
EAC_U07.SPECIMEN_CONTAINER	Specimen Container group	No	No
SAC	Specimen Container detail	Yes	No
SPM	Specimen	No	Yes
CNS	Clear Notification	No	No
ROL	Role	No	No

EAC_U07 sends an equipment command from one application to another, most often from a Laboratory Automation System or middleware component to an analyzer, track, aliquoter, sorter, or storage device.

This is not just "status with an imperative mood." A command can change real equipment behavior, move a specimen, clear a notification, schedule work, or ask the device to perform a defined automation action. Treat it like an operational transaction, not a casual message.

A small EAC U07 example

MSH|^~\&|LAS|CITYHOSP|TRACK01|CORELAB|20260723110500||EAC^U07^EAC_U07|EAC070001|P|2.5.1 EQU|TRACK01^Automation Track 1^CITYHOSP|20260723110500|IDLE^Idle^HL70365|REMOTE^Remote control^L|N^Normal^HL70367 ECD|800101|LOADCARRIER^Load carrier^L|Y^Yes^HL70136|20260723111000|RACK7 TQ1|1||||||20260723111000|||R^Routine^HL70485 SAC|||TUBE12345^CITYHOSP|||||||RACK^Rack^L|RACK7|04 SPM|1|SPEC12345^CITYHOSP||SER^Serum^HL70487 CNS|900100|900120|20260723100000|20260723110000|DU001^Detector drift^L|DU001^Detector drift^L

What workflow it represents

A system with orchestration authority tells equipment to perform an agreed action. The command might load a carrier, move a tube, start a prepared operation, clear a notification, or perform another site-profiled automation step.

The application-level answer is usually EAR_U08. A transport or application ACK only tells you the command message was received; it does not prove the equipment actually completed the command.

How to read the structure

MSH identifies the command event. Optional SFT can describe the sending software. Required EQU identifies the equipment being commanded.

Each COMMAND group starts with required ECD, where the command number, command code, response requirement, requested completion time, and parameters live. Optional TQ1 adds timing.

The optional SPECIMEN_CONTAINER group adds SAC and optional SPM when the command is tied to a container or specimen. Optional CNS clears one or more equipment notifications as part of the command flow.

Implementation traps

The biggest trap is under-specifying the command vocabulary. ECD-2 must be a tightly agreed code set. If "LOAD", "MOVE", and "START" mean different things to the LAS and the device, the interface is not safe to operate.

Make command identifiers durable. ECD-1 is how the EAR_U08 response can be matched back to the command that caused it, especially when multiple commands are in flight.

Be explicit about rejection, timeout, and retry behavior. Integration Soup or another interface engine can monitor command-response pairs, but only if the profile says what a missing or negative response means.

Reference notes

HL7 v2+ describes EAC_U07 as the message for sending equipment commands between applications, for example from a Laboratory Automation System to automated equipment. The local v2.5.1 structure centers on EQU plus repeating ECD-led command groups.