PLC Analog Scaling (27648 / 32767 / 4000)
Two-way conversion between PLC analog codes and engineering values for Siemens 27648, generic 32767 and Mitsubishi/Omron 4000 full scales, with wire-break and over-range detection.
Key points
PLC Analog Scaling (27648 / 32767 / 4000): Two-way conversion between PLC analog codes and engineering values for Siemens 27648, generic 32767 and Mitsubishi/Omron 4000 full scales, with wire-break and over-range detection. Formula: Value = LRV + (code/full-scale code × signal span − signal low)/(signal span) × (URV − LRV). Enter parameters on the DD-CAT IDE online tool page to get results instantly, with a calculation-model diagram that updates with the inputs. S7 unipolar modules map 0–20mA (0–10V) onto 0–27648, so 4mA is about 5530 counts, not zero. Scale with the lower-limit and full-scale counts as your two points rather than mapping 0/27648 to 4/20mA.
Inputs
Value = LRV + (code/full-scale code × signal span − signal low)/(signal span) × (URV − LRV)Calculation model (updates with parameters)
| Engineering value | 37.500 °C | |
| Signal value | 10.000 mA | |
| Percent of signal span | 37.50 % | |
| Loop status | Within range | |
| Lower / full-scale code | 5530 / 27648 | Use these two points for linear scaling in the PLC |
Engineering notes
- S7 unipolar modules map 0–20mA (0–10V) onto 0–27648, so 4mA is about 5530 counts, not zero.
- Scale with the lower-limit and full-scale counts as your two points rather than mapping 0/27648 to 4/20mA.
FAQ
- What is PLC Analog Scaling (27648 / 32767 / 4000) for?
- Two-way conversion between PLC analog codes and engineering values for Siemens 27648, generic 32767 and Mitsubishi/Omron 4000 full scales, with wire-break and over-range detection.
- What is the formula for PLC Analog Scaling (27648 / 32767 / 4000)?
- Core formula: Value = LRV + (code/full-scale code × signal span − signal low)/(signal span) × (URV − LRV). The tool returns results instantly using this formula and the selected parameters.
- What engineering notes should I keep in mind when using PLC Analog Scaling (27648 / 32767 / 4000)?
- S7 unipolar modules map 0–20mA (0–10V) onto 0–27648, so 4mA is about 5530 counts, not zero. Scale with the lower-limit and full-scale counts as your two points rather than mapping 0/27648 to 4/20mA.