Type descriptor
From the LabVIEW Help:
LabVIEW associates each wire and terminal on the block diagram with a data type. LabVIEW keeps track of this type with a structure in memory called a type descriptor. This type descriptor is a sequence of 32-bit integers that can describe any data type in LabVIEW. Numeric values are written in hexadecimal format, unless otherwise noted.
List of TD types
| TypeDesc ID | Description |
|---|---|
| 0x00 | Void type, stores no data |
| 0x01 | Integer with signed 1 byte (8 bit) data |
| 0x02 | Integer with signed 2 byte (16 bit) data |
| 0x03 | Integer with signed 4 byte (32 bit) data |
| 0x04 | Integer with signed 8 byte (64 bit) data |
| 0x05 | Integer with unsigned 1 byte (8 bit) data |
| 0x06 | Integer with unsigned 2 byte (16 bit) data |
| 0x07 | Integer with unsigned 4 byte (32 bit) data |
| 0x08 | Integer with unsigned 8 byte (64 bit) data |
| 0x09 | Floating point with single precision 4 byte data |
| 0x0A | Floating point with double precision 8 byte data |
| 0x0B | Floating point with extended (quad precision) data |
| 0x0C | Complex floating point with 8 byte data |
| 0x0D | Complex floating point with 16 byte data |
| 0x0E | Complex floating point with extended (quad precision) data |
| 0x15 | Unit UInt8 |
| 0x16 | Unit UInt16 |
| 0x17 | Unit UInt32 |
| 0x19 | Unit Float32 |
| 0x1A | Unit Float64 |
| 0x1B | Unit FloatExt |
| 0x1C | Unit Complex64 |
| 0x1D | Unit Complex128 |
| 0x1E | Unit ComplexExt |
| 0x20 | Boolean value stored on 2 bytes (16 bit), rarely used |
| 0x21 | Boolean value stored on 1 byte (8 bit) |
| 0x30 | String value |
| 0x31 | Variation of String value, probably never used |
| 0x32 | Path value, used for disk paths, sometimes for URLs |
| 0x33 | Picture data |
| 0x34 | CString |
| 0x35 | PasString |
| 0x37 | Tag |
| 0x3F | SubString |
| 0x40 | Array |
| 0x41 | Array Data Ptr |
| 0x4F | SubArray |
| 0x50 | Cluster |
| 0x53 | Variant data type |
| 0x54 | Measurement data |
| 0x5E | Complex fixed point number |
| 0x5F | Fixed point number |
| 0x60 | Block |
| 0x61 | Type block |
| 0x62 | Void block |
| 0x63 | Aligned block |
| 0x64 | Repeated block, stores |
| 0x65 | Alignment marker |
| 0x70 | Refnum; has multiple sub-types |
| 0x80 | Ptr |
| 0x83 | Ptr to |
| 0x84 | Ext Data |
| 0xA0 | Array interface |
| 0xA1 | Interface to data |
| 0xF0 | Function |
| 0xF1 | TypeDef |
| 0xF2 | PolyVI |