Number range¶
Integer word (16 bits)
| Low limit | 8001H | -32767 |
| High limit | 7FFFH | +32767 |
| Inadmissible value | 8000H | — |
The following especially applies here to the specification for the left edge of the hysteresis:
E2 - HYS ≥ -32767 (8001H)
In the two’s complement arithmetic, the value 8000H (-32768) lies outside of the number range and is neither generated nor processed correctly by the PLC. If this forbidden value reaches the PLC
- by bit manipulations of the user or
- by reading from outside the PLC or
- by an indirect word constant
it is absolutely not allowed to carry out a negation or subtraction on this value.