Projects/Liberty/File Formats/Tajima Ternary
Tajima Ternary DST
This is based on an old paper tape format, thread colour is not usually stored in the file. At each thread change stop, the thread colour has to be found in an external source; the embroidery machine usually gives needle number or stitch count at each stop.
The file is in two parts: a textual header part of 512 bytes and a binary stitches part. Each stitch has attributes indicating: normal stitch, jump stitch, colour change stop, and end of pattern stop.
The textual part is said not to be very accurate and is more user information. It does have data to link to a previous tape or file which is rarely used.
Appliqué is used extensively in commercial embroidery (probably to save time), I think the colour change stop is also used for cutting the pieces (or placing precut pieces) before embroidering their edges. In home appliqué a baste stitch is often used to the pieces in place.
In the style of Backus-Naur Form,
file = header {stitch}
Header
The header is 512 ASCII characters containing fields, although the fields could be variable length, they appear to be fixed width and fixed offset. A field is labelled by a two letter code and a colon, then the value and terminated by an ASCII carriage-return CR (0/13). The fields are terminated by ASCII Control-Z (1/10) and sometimes the space following is used for colour information, otherwise it is padded with ASCII space (2/0).
| Offset | Size | Type | Description |
|---|---|---|---|
| 0 | 20 | ASCII | = "LA:" (label) Name padded with spaces 0x20, sometimes terminated with nul 0x00 |
| 20 | 11 | ASCII | = "ST:" (stitch count) decimal number padded with zero or space |
| 31 | 7 | ASCII | = "CO:" (colour count) decimal number |
| 38 | 9 | ASCII | = "+X:" (maximum X extent) decimal number in tenths of a millimetre |
| 47 | 9 | ASCII | = "-X:" (minimum X extent) decimal number in tenths of a millimetre |
| 56 | 9 | ASCII | = "+Y:" (maximum Y extent) decimal number in tenths of a millimetre |
| 65 | 9 | ASCII | = "-Y:" (minimum Y extent) decimal number in tenths of a millimetre |
| 74 | 10 | ASCII | = "AX:" (needle end point X) "+" or "-" decimal number in tenths of a millimetre |
| 84 | 10 | ASCII | = "AY:" (needle end point Y) "+" or "-" decimal number in tenths of a millimetre |
| 94 | 10 | ASCII | = "MX:" (previous file needle end point X) "+" or "-" decimal number in tenths of a millimetre |
| 104 | 10 | ASCII | = "MY:" (previous file needle end point Y) "+" or "-" decimal number in tenths of a millimetre |
| 114 | 10 | ASCII | = "PD:" (previous file) "******" if single file |
| 124 | 4 | ASCII | = 0x1a 0x20 0x20 0x20 or 0x1a 0x00 0x00 0x00 end of header data |
| 128 | 384 | ASCII | = spaces 0x20 or sometimes contains colour information |
The multiple file or tape fields: AX, AY, MX, MY, and PD are seldom used.
Stitch
Each stitch is 3 bytes.
| Offset | Size | Type | Description |
|---|---|---|---|
| 0 | 3 | Code | 24 bit big-endian bit set |
Stitch Code Bits
The end of pattern has the code value 0x0000F3, otherwise see table below.
| Bit | Description |
|---|---|
| 23 | Y += 1 add 0.1 mm to needle's Y current coordinate |
| 22 | Y -= 1 subtract 0.1 mm from the needle's current Y position |
| 21 | Y += 9 |
| 20 | Y -= 9 |
| 19 | X -= 9 |
| 18 | X += 9 |
| 17 | X -= 1 |
| 16 | X += 1 |
| 15 | Y += 3 |
| 14 | Y -= 3 |
| 13 | Y += 27 |
| 12 | Y -= 27 |
| 11 | X -= 27 |
| 10 | X += 27 |
| 9 | X -= 3 |
| 8 | X += 3 |
| 7 | Jump stitch (not a normal stitch) |
| 6 | Stop for colour change or end of pattern |
| 5 | Y += 81 |
| 4 | Y -= 81, the end-of-pattern code sets both Y += 81 and Y -= 81 which cancel each other |
| 3 | X -= 81 |
| 2 | X += 81 |
| 1 | = 1 synchronization bit |
| 0 | = 1 synchronization bit, two LSB only set in byte 3 |
Several jump stitches may be run together to span distances greater than 12.1 mm, the following normal stitch is the start of the next run of stitches (don't draw a line from the last move stitch to the following normal stitch).
References