What is a slave file, and who can open it?

If you have ever been sent a file you could not open, this is usually why. The file looks normal, it has a name and a size, and your editor refuses it or shows you nonsense. It was read by a slave tool, and it is locked to somebody else.

Why are slave files locked?

The lock is how the tool makers make the master and slave model work. A slave costs less than a master, and in return its files go to one place. The lock also protects the master: a slave they have trained and supported cannot quietly send its work elsewhere.

So a locked file is not damaged or wrong. It is just addressed to someone.

Who can open a slave file?

Only its master, using the maker's own software or the maker's service. There are three situations a file service runs into:

The third row causes most of the trouble. A customer who changes file service may still be holding a slave tied to their old one. Their files will not open for you, however good your tools are.

What should you ask before accepting a file?

Two questions save a lot of time. Which tool did you read it with? And is that tool a slave, and whose? The tool is already on the order page, so it stays on the job. If the file is tied to someone else, say so straight away and suggest they ask their master about moving the slave.

A locked file is not a broken file. It is a file addressed to someone else.

What can a portal do with a locked file?

It depends on the maker. A portal can accept and store any file, because a file is only bytes until someone opens it. Opening it is another matter.

On a TunerEngine portal, if you are a master on Alientech or AutoTuner, you connect your own account in your portal's settings and their locked files open on the job. The tuned file then goes back encrypted for the customer's tool. It all runs on your account, never on ours. Files from other makers are kept as they came, and your tuner opens them in that maker's tool and uploads the result. The guide on locked files walks through it step by step.

What happens to the file afterwards?

Every job keeps the read as it came, the decrypted copy when there is one, the tuned file, and the encrypted copy when one was made. That matters when a customer comes back with a question months later, because you can see exactly what you received and exactly what you sent.