The DCL logout command when used inside a sub process causes that process to exit to the parent process. Inside a top level process it will cause that batch job to terminate immediately at that point. The standard post-amble that is added by EnterpriseSCHEDULE collects usage statistics from the job. The use of logout will skip these. To prevent this the schedule_login.com procedure redefines logout when inside a EnterpriseSCHEDULE job to allow these statistics to be gathered and proceeds with the exit.
If you are running a release prior to v7.5 and have not installed the schedule_login.com (and the 4 other files listed earlier) it is recommended that you not use logout. But instead use a goto to branch to the bottom of your DCL commands.