How do I build and debug a 3270/5250 Screens Flow?

Q: How do I build and debug a 3270/5250 Screens Flow?

Build Hub terminal Screens Flows for 3270/5250: capture trails, identifiers, conditions, and debug with Test Flow or OL Terminal Play Flow.

Hub terminal Screens Flows automate a live 3270/5250 session — identify screens, send AID keys, map fields, and branch on the current screen. This is not BMS/MFS map APIs (OL Screener / OL Next).

Typical path

Create a Mainframe Screens or AS/400 Screens module and connection in OL Integration.
Capture screens from a trail/emulation session (or import screen entities). OL TermIQ can help name and catalog screens from recordings.
Create a contract — optionally auto-generate from the trail — then refine the SCREENS flow (SCREEN_INVOKE, conditions, firstScreenId).
Test in Hub Test Flow, or step the same method against a live session with Play Flow in OL Terminal.

What usually breaks

Identifiers — if two screens look alike, the wrong entity is selected after an AID.
Popups / extra screens — add a condition or an extra invoke; do not assume a linear path.
Multi-page tables — paging is a navigation loop, not a single capture.
Conditions not firing — the current-screen check must match the identifier of the screen actually on the host.

See Screens Flow Methods for the full model.