It should be a constantly updated code operating on an algorithm. Even 24 hours is too long. So much can go wrong in that time and invasions only take a foothold to get started.
They never cover it but the codes are probably one time use as well. I remember one of the early episodes SG1 is under tight time constrains because the GDO is going to be locked out soon. I think it’s one they recruit Teal’c but I’m not sure.
It should be a constantly updated code operating on an algorithm. Even 24 hours is too long. So much can go wrong in that time and invasions only take a foothold to get started.
They never cover it but the codes are probably one time use as well. I remember one of the early episodes SG1 is under tight time constrains because the GDO is going to be locked out soon. I think it’s one they recruit Teal’c but I’m not sure.
The first couple episodes they mention that. But I always assumed that meant the codes were on a per mission basis.
Then it doesn’t explain Cold Lazuras where jack comes back after everyone or when the evil team came through in the last season to nick the zpm.
I always assumed it worked like an actual garage door opener and had rolling codes.