Wiring¶
Wiring
| Bus line | |
|---|---|
| Construction | 2 cores, twisted, with common shield |
| Conductor cross section | > 0.22 mm² (24 AWG) |
| - recommendation | 0.5 mm² corresponds to ˜ 0.8 mm |
| Twisting rate | > 10 per meter (symmetrically twisted) |
| Core insulation | Polyethylene (PE) |
| Resistance per core | < 100 Ω/km |
| Characteristic impedance | ca. 120 Ω (100…150 Ω) |
| Capacitance between the cores | < 55 nF/km (if higher, the max. bus length must be reduced) |
| Terminating resistors | 120 Ω ¼ W at both line ends |
| Remarks | Shielded cables with PVC core insulation and a core diameter of 0.8 mm can be used up to a length of ca. 50 m. In this case, the bus terminating resistor is ca. 100 Ω. |
Remarks:
Cables with PVC core insulation and a core diameter of 0.8 mm can be used up to a length of ca. 250 m. In this case, the bus terminating resistor is ca. 100 W.
Cables with PE core insulation can be used up to a length of ca. 500 m.