The main operator station on a web-fed printing press is where speed, registration, count, and fault response all converge. On machines using a GOT97 touchscreen with PLC bus communication, the interface is split across five screens that cover setup, run control, stepper adjustment, and diagnostics. Here’s how each screen works and how to configure the key parameters.
Screen 1: Parameter Setup
This screen displays live production data — press speed, folder count, bundle count, and marker count — alongside controls for starting, pausing, and resetting counters, selecting web lead mode, and choosing turner bar position.
Four critical parameters get set here:
- Paper weight: 30-120 g/m², 1 g precision. Changing this value automatically recalculates hole pitch and infeed roller speed. The value is stored in PLC register D310.
- Print format: Stored in D311.
- Bundle count: Stored in D305.
- Folds per marker: Stored in D306.
The input procedure is the same for all four: press the parameter key to open the data entry window, press Start, enter the value on the on-screen numeric keypad, press Enter to store it to the PLC, then press Stop to close the input. Press the parameter key again to exit.
Web Break and Splice Detection
Two safety toggles on this screen — Web Tail ON and Splice Detection ON — must be active for the corresponding sensors to function. The web tail sensor position depends on which side the roll is loaded: M for the operator side, G for the drive side. Selecting the wrong side disables detection.
Screen 2: Running Control
This is the operator’s primary screen during production. It shows speed and fold count, and gives access to:
- Unit selection: Required before any unit-level adjustment — trim, spray, or register move.
- Circumferential register jog: Each press of the jog key moves the selected unit 0.1 mm in the chosen direction. Hold the key for continuous movement.
- Manual spray dampening: Hold the spray key for the selected unit; release to stop.
- Edge hole fine trim: Press jog keys to shift the edge hole position incrementally.
- Folder adjustment: Jog keys move the folder position as selected.
- Manual marker: Press and hold to apply a marker; release to stop. When the marker counter is active and reaches its set value, a 0.3s automatic marker fires.
Speed and Tension Settings
Three ratio values are set on this screen:
- Guide roller speed ratio: -100% to +100%, 1% resolution. Controls the circumferential speed of the guide roller relative to the web.
- Hole pitch (repeat length): -10 mm to +10 mm, 0.01 mm resolution, referenced against a 3m base pitch.
- Infeed roller tension ratio: Sets speed differential for tension control at the unit infeed and outfeed rollers.
Pitch and tension settings ultimately depend on web thickness, infeed length, and roller speeds at processing unit entry and exit. Data is stored temporarily in the D register area and read by the PLC program when the input operation closes.
A unit conversion button and screen navigation keys round out this page.
Screen 3: Stepper Motor Control
This screen drives stepper motor adjustments by numerical input. The procedure:
- Select the unit to adjust — the data entry window opens automatically.
- Press Start, enter the value on the numeric keypad, press Enter to store it in the PLC D-register, then press Stop to close the input.
- Press NC Start to execute the move. Press NC Stop at any point to abort.
Screens 4 & 5: Fault Diagnostics
When the machine faults, the fault screen overrides the current display automatically. The fault point is highlighted with a flashing indicator at the corresponding machine position. A yellow-background, black-text flag signals that touching that area opens a detail window with more granular fault location data. Pressing Close returns to the run screen.
The number of screens is flexible — determined by the machine’s functional scope, not a fixed layout.
References
- Wikipedia: Programmable Logic Controller (PLC): Overview of PLC architecture, ladder logic, data registers, and industrial communication protocols used in printing press control systems.
- Wikipedia: Web Offset Printing: Description of web-fed printing press architecture including infeed, tension control, folder, and operator station functions.
- ISO 12647-4:2014 — Gravure Process Control: International standard for process control parameters including register tolerance and color consistency relevant to operator station monitoring.
- Wikipedia: Human-Machine Interface (HMI): Fundamentals of industrial HMI design including GOT series touchscreens, screen navigation patterns, and PLC communication architecture.
- Wikipedia: Stepper Motor: Operating principles of stepper motors including numerical control, step angles, and positioning accuracy used in register and folder adjustment systems.