Signing On to Connect:Direct for z/OS
The SIGNON command establishes your session with the DTF so that you can issue commands.
You can control access to the IBM® Connect:Direct® system through the IBM Connect:Direct Authorization Facility and security exits. For information on security control, go to the IBM Connect:Direct for z/OS® Administration Guide and search for Implementing Security.
If you are using the Extended Submit Facility (ESF), you can submit the SIGNON command even though the DTF is inactive.