The first two systems I worked with using InterSystems technology were a PDP-11 running M11+ and a VAX 11/750 running M/VX. Too many years ago to count! 😊
Since then I've used most, if not all, InterSystems products up to IRIS and HealShare today.
I'm italian living in Switzerland and I work as Senior Consultant at GAIVOTA consultin SA, we provide professional services for InterSystems and other technologies.
Curiosity: apart from DC, I don't have ANY social account! 😁
For the incoming HL7 messages, does the field MSH:CharacterSet (MSH:18) contains a value? Is so, what's the value?
You write that the receiver message is encoded using utf-8, have you tried to configure the "Default Char Encoding" setting in the Business Service to "utf-8"?
If the incoming HL7 message is actually/really encoded using utf-8 and MSH:18 contains a value different than "utf-8", you can enforce conversion configuring the "Default Char Encoding" setting in the Business Service to "!utf-8".
I hope the message is not malformed and contains data/fields with different codes, if so...it can be tricky.
Character set conversion should be /configured/applied in the receiving service/adapter.
Unfortunately you did not provide any useful details, so it's impossible to help.
First you MUST be positively sure on what the character set is actually used in the incoming HL7 message.
What's the character set of the incoming message?
If it's really utf-8 then setting "Default Char Encoding" to utf-8 should work, if it does not, then evidently the incoming message use a different character set.
Just in case, try setting "Default Char Encoding" to "!utf8"