Presentation (only when using PDO SINT16)
For historical reasons, there are various formats in which the 16 bits of the SINT PDO (Signed Integer Process Data Object) can be interpreted.
The format can be set in the index 80n0:02 .
Fig.228: PDO 80n0:02, "Presentation"This analog channel supports:
- "Signed" (default): top/highest/0. Bit is sign, negative number in 2's complement in bit 1..15
- "Unsigned": all 16 bits are used for the amount of the analog value, resulting in double resolution for positive analog values. No transmission of negative values possible.
- "Absolute Value with sign": top/highest/0. Bit is sign, bits 1..15 carry the amount of the analog value
- "Absolute Value": the sign of the analog value is ignored, only the (positive) amount in bit 1..15 is transmitted
Legacy Range | Extended Range | Representation (values dec. / values hex.) | |||
|---|---|---|---|---|---|
unsigned integer | Abs. value w. MSB as sign | ||||
Dec | Hex | Dec | Hex | ||
100% | 107.37% | 32767 | 0x7FFF | 32767 | 0x7FFF |
- | 100% | 30518 | 0x7736 | 30518 | 0x7736 |
0% | 0% | 0 | 0x0000 | 0 | 0x0000 |
- | -100% | 30518 | 0x7736 | [-30518] | 0xF736 |
-100% | -107.37% | 32767 | 0x7FFF | [-32767] | 0xFFFF |
 | Presentation types The presentation types "Unsigned integer" and "Absolute value with MSB as sign" have no function for unipolar terminals. There is no change in the presentation in the positive range. |