Sales Order Combined DMT; Lot Number not setting?

[Aaron_Moreng]

I am creating a Sales Order Combined DMT file to pass over to another company for an integration.
All is working well except for it is not setting the OrderDtl#LotNum field value.
I assume this is a settable field, but perhaps it isn’t?

Template:

Sales Order:

The Lot num appears to be the only thing not being set and otherwise the data is flowing exactly as designed.
Any tips are appreciated!

[ckrusen (Calvin Krusen)]

Do those lot numbers already exist in the target system?

[Aaron_Moreng]

Oh I didn’t know they had to be, so you’re saying it has to exist before I can write it? I’ll try that , thanks