SENAITE.LIS2A allows to setup custom interpreters to handle messages differently, depending on a user-defined criteria. The most common scenario is to have a different interpreter for each instrument. Multiple interpreters for same instrument but used based on different criteria are also supported.

You need first to create a folder in your add-on and register it as a resources directory for type senaite.lis2a.interpreters in configure.zcml as follows:

<!-- resource directory for LIS2A2 interpreters -->
    type="senaite.lis2a.interpreters" />

Note that in this case, the name of the folder is “interpreters”.

Then, you only need to create a file in json format representing the interpreter with your own criteria and mappings. System will only consider files ending with the extension “.json”.

For example, given a message like the following:

H|\^&|9||cobas infinity^Roche Diagnostics^^3.03.12|||||cobas infinity ^Roche Diagnostics||P||20221021184225
R|1|^^BCRBT^77140-2|44|µmol / l|[44.2 - 132]|||F||||20221021184219
R|2|^^BUN^1996-8|4|mmol / l|[2.2 - 2.7]|||F||||20221021184219
R|3|^^CHLRD^59570-2|5|mmol / l|[3.5 - 7.1]|||P||||20221021184218

we can create a file “cobas_infinity.json” representing an interpreter with the criteria and rules for the import of the message above:

  "extends": "LIS2-A2",
  "selection_criteria": {
    "H.SenderName": "cobas infinity"
  "result_criteria": {
    "R.ResultStatus": "F"
  "mappings": {
    "id": [
    "keyword": [
    "result": "R.Measurement",
    "ranges": "R.ReferenceRanges",
    "units": "R.Units",
    "capture_date": "R.DateTimeCompleted",
    "captured_by": [
  "O": {
    "InstrumentSpecimenID": [3,2]

Note that this interpreter extends from another interpreter, called LIS2-A2. The LIS2A-2 interpreter provides the basic mappings and positional information from records and values as defined in the standard.

When a LIS2-A2 message is received, the system first checks if the message matches with the criteria set under selection_criteria parameter. If all criteria are met, system considers that the given interpreter supports the message and will therefore be used to extract and import results. Otherwise, the system skips the interpreter and keeps searching in resources directory until a suitable interpreter is found.

When the results records from the LIS2-A2 message are processed following the rules defined in the interpreter, the system takes the result_criteria into consideration to whether try or not try to import the result record. Going back to the example above, the last results record won’t be imported because the value for ResultStatus is not F (Final), but `P`(Preliminary):

R|3|^^CHLRD^59570-2|5|mmol / l|[3.5 - 7.1]|||P||||20221021184218

After results from the message are filtered in accordance with the criteria above, system tries to import the results in accordance with the information provided in mappings.