Free tool · PROFIBUS
PROFIBUS baud rate ↔ distance calculator
PROFIBUS DP/FMS on RS-485 type A imposes a baud rate / segment distance trade-off, plus a 32-device-per-segment limit and a 126-device total cap with repeaters (max 9 repeaters in cascade). This validator checks your config live.
Free · no sign-upLast updated: 2026-05-20
m
Meters of RS-485 cable
Master + slaves (126 total max)
✅ Valid configuration
- Max distance per segment
- 200 m
- Segments needed
- 2
- Repeaters needed
- 1
Reference baud rate ↔ max segment distance
| Baud rate | Max segment distance |
|---|---|
| 9.6 kBit/s | 1200 m |
| 19.2 kBit/s | 1200 m |
| 45.45 kBit/s (PA-compatible) | 1200 m |
| 93.75 kBit/s | 1200 m |
| 187.5 kBit/s | 1000 m |
| 500 kBit/s | 400 m |
| 1.5 MBit/s | 200 m |
| 3 MBit/s | 100 m |
| 6 MBit/s | 100 m |
| 12 MBit/s | 100 m |
How to use
1. Pick your project baud rate (1.5 Mbps is the typical PROFIBUS DP standard).
2. Enter the actual cable run length.
3. Enter the total device count.
4. The tool confirms compliance and gives the segments + repeaters needed.
5. For type A cable: 220 Ω / 390 Ω / 390 Ω terminations on both ends are mandatory.
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