Global Counter throughout channels

Hi, so I'm using Mirth Connect 3.0.3.7171 and I'm curious if there is someway to have a global counter (can be accessed in different channels) without losing its value. I need this because I am building several HL7 messages in different channels and their Message Id has to be different (MSH.10). I'm not sure if using a variable in globalMap would be the best approach since I'm not aware of one's lifetime.



Any ideas, on how to do this?



Best regards, Andre.

Global Counter throughout channels