Reply To: How to overcome OBX-5 size limit?

[Jim Kosloskey]

Kevin,

Since you are concerned about using the Reference Pointer in the OBX segment, here is some information:

The use of a Reference Pointer in the OBX requires that OBX-2 field be valued with ‘RP’ (RP is the Reference Pointer HL/7 Data Type).  The OBX-2 field indicates the Data Type of the OBX-5 field.

Now the actuual Pointer will be in the OBX-5 field.

The RP Data Type has a specific structure. That is covered in detail in Chapter 2 of the HL/7 standard (I think it is Chapter 2 of any 2.x version).

I am pretty sure the RP Data Type is not specified in version 2.1. I know it exists in version 2.3 and beyond.

Essentially this is the construct of the RP Data Type:

Component-1 : Pointer (ST Data Type Component). This is where the actual pointer goes.

Component-2: Application ID (HD Data Type Component)

   This consists of 3 sub-components (typically separated by the &):

           Namespace ID (IS Data Type)

           Universal ID (ST Data Type)

           Universal ID Type (ID Data Type)

   This component is used to identify the Application that houses the object pointed to by the pointer.

Component-3: Type of Data (ID Data Type). There is a Table in the standard that indicates possible/recommended values but this essentially states the general category of the data that will be foind in the object pointed to by Component-1.

Component-4: Subtype (ID Data Type). There is another Table in the standard that contains possible/recommended values. The standard also describes how to specify local entries to both the Type of Data and subtype Tables for exceptoins to what is in the respective Tables. This is a component which further clarifies Componenet-3. For example if the code in Component-3 indicated Image Data Component-4 might indicate RTF (Rich Text Format).

If you decide to use a Reference Pointer in the OBX – might as well do it corectly and follow the standard.

You have 2 options as I see it within Cloverleaf(R) Xlate:

1. Change the Data  Type for field ‘Observation Value’ in the inbound and outbound variant from ‘ST’ to ‘RP’ and then you will see all of the components that make up the RP Data Type (but not the sub-components because the Xlate does not present those in the message tree).

2. Leave the ‘Observation Value’ Data Type alone (ST) and use the component and subcomponent notation by typing it in yourself with each reference.

There may be other resolutions…

email: jim.kosloskey@jim-kosloskey.com 30+ years Cloverleaf, 61 years IT – old fart.