Hi Yakov,

I'm not sure which class you are using for your service, some assumptions will be made below:

In general, the service framing is regarding the Startblock(s) (before MSH) and Endblock(s)(at the end of the entire Hl7 Message), and not regarding the Segment Terminators.

First resolution:

Have the source send a correctly formatted HL7 message, as it appears they are utilizing a start and endblock on each segment instead of only a single time per HL7 message.

Second resolution:

I'm not aware of any direct out of the box way of explicitly set the segment terminators,  so an additional custom class may need to be created. I would look into the method GetSegmentTerminator of  EnsLib.HL7.Service.Standard class.