Documentation sections

LIN Bus Timing Calculator

POSThttps://rftools.io/api/py/v1/calculate

Slug lin-bus-timing. Calculate LIN bus bit time, break field length, frame time, and maximum frame rate for automotive LIN network design.

Inputs

Send every one of these in inputs, in the units shown. Most are required: a call without one is refused (400) and costs nothing; one the calculator can do without takes the default shown. An input outside its range is still computed and flagged in the provenance.

Inputs of lin-bus-timing
Name	Unit	Range	Default	Description
baudRatenumber	kbps	0.1 … 20	19.2	LIN baud rate (typical: 2.4, 9.6, 10.4, 19.2 kbps)
dataBytesnumber	bytes	1 … 8	8	Number of data bytes in the response field (1-8 per LIN spec)
slotTimenumber	ms	0.1 … 1000	10	The schedule table's time for this frame; LIN 2.x needs it to hold the frame at its 1.4 × nominal maximum

Outputs

Returned in values, by key. A value that is unbounded or undefined is null.

Outputs of lin-bus-timing
Field	Unit	Description
bitTime	μs	Duration of one bit: T_bit = 1 / baud_rate
breakLength	μs	Minimum break field duration (13 bit times)
frameTimeheadline	μs	Total LIN frame duration including header and response
framesPerSec	frames/s	Maximum frames per second at this baud rate and data length
busLoad	%	Approximate bus utilization percentage
frameTimeMax	ms	The frame time with its 40 % allowance for inter-byte spaces and the response space (LIN 2.x TFrame_Maximum); the schedule slot must hold it

Calling it

Calculate: one call, the request and response in full, and its errors.
Batch: this calculator with others, or a sweep, in one request.
Solve for a target: the value of one input that brings an output to a target.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "lin-bus-timing",
    "inputs": {
      "baudRate": 19.2,
      "dataBytes": 8,
      "slotTime": 10
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("lin-bus-timing", {"baudRate": 19.2, "dataBytes": 8, "slotTime": 10})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "lin-bus-timing",
    "inputs": {
      "baudRate": 19.2,
      "dataBytes": 8,
      "slotTime": 10
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "lin-bus-timing",
	  "inputs": {
	    "baudRate": 19.2,
	    "dataBytes": 8,
	    "slotTime": 10
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "lin-bus-timing",
  "values": {
    "bitTime": 52.083333333333336,
    "breakLength": 677.0833333333334,
    "frameTime": 6458.333333333334,
    "framesPerSec": 154.83870967741933,
    "busLoad": 96.875,
    "frameTimeMax": 9.041666666666666
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:lin-bus-timing",
    "version": "api@3f2c1a9b04de",
    "formulaRef": "LIN Specification Package Revision 2.2A",
    "assumptions": [],
    "validRange": {
      "status": "inside",
      "bounds": {
        "baudRate": {
          "min": 0.1,
          "max": 20,
          "unit": "kbps"
        },
        "dataBytes": {
          "min": 1,
          "max": 8,
          "unit": "bytes"
        },
        "slotTime": {
          "min": 0.1,
          "max": 1000,
          "unit": "ms"
        }
      },
      "outside": [],
      "model": null
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "baudRate": 19.2,
      "dataBytes": 8,
      "slotTime": 10
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "baudRate"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

An input sent as text. Nothing was counted.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Too many requests in a minute, with Retry-After.

Same inputs on the calculator pageLIN Bus Timing Calculator, at these values