^FH — Field Hex Indicator
Plain English
Defines an **escape character** that the next `^FD` will use to introduce hex byte sequences. Default is underscore (`_`), but you can supply any single ASCII character as the argument (commonly `\`). Each escape pair (`_NN` or `\NN`) decodes to a single byte — letting you embed control characters (newline `_0A`, tab `_09`), special symbols (`_5E` for `^`, `_7E` for `~`), or non-ASCII bytes that the printer would otherwise treat as syntax.
When to use
Immediately before the `^FD` whose data needs hex escapes. Scope is the next `^FD` only — repeat `^FH` for every field that needs it. Pair with `^CI` for non-ASCII text encoded as hex.
Syntax
^FH_
Parameters
| Parameter | Description |
|---|---|
esc | Single character used to introduce hex escape sequences (default `_`). Common alternatives: `\` or `~`. |
Example
^XA ^FH\ ^FO50,50^A0N,30,30^FDLine 1\0ALine 2^FS ^XZ
`^FH\` declares `\` as the escape character; `\0A` decodes to a newline byte, splitting the field into two lines.