Paper Tape Emulators
| General (used on Dubied & Stoll) GNT Reader / Emulator | |
|---|---|
| Manufacturer | General (used on Dubied & Stoll) |
| Model | GNT Reader / Emulator |
| Gauge | N/A |
| Type | Industrial Accessory |
| Patterning | Paper Tape / RS-232 Serial |
| Needles | |
| Release Year | 1970s - 1980s |
| Accessories | |
| Also Known As | |
Paper Tape Emulators are hardware interfaces used to modernize legacy industrial knitting machines from the 1970s and 1980s. During this era, manufacturers such as Dubied (specifically computerized V-bed models like the JET 2 and JET 3), early Stoll (CMS series), and early Shima Seiki models relied on physical punched paper tape readers (such as GNT paper tape readers) to load garment patterns and knitting programs into the machine's control memory.[1]
Because physical paper tapes are prone to tearing, degradation, and are difficult to create using modern computers, paper tape emulators replace the mechanical tape reader, allowing patterns to be loaded digitally via USB, SD card, or serial connection (RS-232).
Historical Context[edit]
Early electronic knitting machines had very limited onboard memory. Patterns designed on early CAD-CAM systems (like Dubied's DUCAD system) were compiled and punched onto 8-channel paper tapes using a mechanical paper punch. These tapes were then carried to the factory floor and fed through a photoelectric paper tape reader connected to the knitting machine's controller.
A single complex garment pattern could require hundreds of feet of paper tape. If the tape tore or suffered a misread during loading, the knitting machine could not operate, leading to production downtime.
How Emulators Work[edit]
A paper tape emulator connects directly to the knitting machine's controller board, plugging into the identical port used by the original GNT or reader interface.
- Interface Simulation: The emulator electrically mimics the signals of the mechanical tape reader, responding to the machine's read commands (such as step signals) as if paper tape were physically passing through the reader.[2]
- Digital Storage: Instead of physical tape, the pattern files (often in standard raw formats) are stored on an SD card or transferred dynamically from a PC over an RS-232 serial connection.[3]
- Data Transfer Control: The emulator manages flow control (using hardware handshaking or software XON/XOFF protocols) to feed the data at a speed the machine's legacy processor can handle.[4]
Applications in Knitting Machines[edit]
- Dubied JET 2 & JET 3: These classic industrial V-bed machines are frequently retrofitted with paper tape emulators (often custom-built using Arduino or SD-card reader modules) to read DUCAD pattern files without physical paper tape punchers.
- Early Stoll CMS series: Used to load pattern files from early Stoll programming terminals directly into the machine.[1]
Benefits[edit]
- Reliability: Eliminates mechanical reader failures (such as dirty optical lenses, worn drive gears, or broken paper tape channels).
- Workflow Modernization: Allows designers to transfer pattern files directly from modern CAD software via USB or SD cards.[4]
- Preservation: Keeps vintage industrial knitting machines operational when replacement mechanical tape readers are no longer manufactured or repairable.