4-Wire P-NET cable
4-WIRE P-NET specifies the use of a shielded cable having 2 individual twisted pairs.
The communication pair must have a characteristic impedance of 100 to 120Ω and a minimum core cross-section of 0.22mm² / 24 AWG. To ensure maximum signal integrity over long bus cables, it is recommended that the core cross-section of the communication pair be increased.
| Bus length | Recommended core cross-section |
|---|---|
| 0 - 100m | Minimum 0.22 mm² / 24 AWG |
| 100 - 400m | Minimum 0.34 mm² / 22 AWG |
| 400 - 1200m | Minimum 0.50 mm² / 20 AWG |
The size of the power pair should be calculated in consideration of maximum current, voltage drop, cable resistance, bus length etc.
Cable, recommended for 4-WIRE P-NET
Cable for 4-WIRE P-NET must be carefully selected to ensure stable communication as well as for providing sufficient power for all devices.
| Resistance in wire mm2 | AWG | Ω/km |
|---|---|---|
| 0.21 | 24 | 88 |
| 0.25 | 72 | |
| 0.34 | 22 | 52 |
| 0.5 | 34 | |
| 0.52 | 20 | 34 |
| 0.75 | 23 | |
| 0.82 | 18 | 22 |
| 1.0 | 18 | |
| 1.31 | 16 | 13 |
| 1.5 | 11 | |
| 1.68 | 15 | 10.4 |
| 2.08 | 14 | 8.5 |
| 2.5 | 7 | |
| 2.6 | 13 | 6.7 |
The values in the above table are only intended as a guide; wire cross section area and resistance vary by cupper alloy, number of stranding etc.
