JT/T 808 0x0200 Location Decoder

Decode alarm, status, coordinates, altitude, speed, direction and BCD time.

Protocol scope and method

The base body is parsed separately from optional extra-information TLVs. Latitude and longitude use unsigned integer values scaled by 10⁶.

lat = uint32 / 1,000,000; speed = uint16 / 10 km/h.

Diagnostic scenario

Extract only the 0x0200 message body after a valid common header. Decode the 28-byte base section, apply hemisphere status bits to coordinate signs and compare time, speed and coordinates with a redacted device event before parsing optional extra-information TLVs.

How to interpret the result

The base result is meaningful only with the accompanying status word. Zero coordinates can represent a real value or absent positioning depending on status and profile. Remaining bytes are not an error; they may be standard or vendor extra-information records.

Input reference

0x0200 body hex
Example default: Sample input included

Common mistakes

  • Using an unredacted production capture with vehicle, credential or network identifiers.
  • Applying coordinate scaling without hemisphere and positioning status.
  • Treating a successfully parsed sample as standards compliance or interoperability proof.

Before using the result

  1. Confirm the protocol edition, transport framing and vendor profile before interpreting fields.
  2. Check the 28-byte base boundary before decoding optional TLVs.
  3. Keep a redacted known-good and known-bad sample as a regression pair.

Questions to check during diagnosis

Does the JT/T 808 0x0200 Location Decoder leave my browser?

No application upload is used. Avoid putting sensitive production data in shareable URLs.

Is this a standards compliance test?

No. Confirm the edition and vendor profile with licensed documents and your target platform.

Offline diagnostic aid. Verify fields, version and vendor extensions before production use.

Detailed engineering guide

JT/T 808 frame diagnostics: boundaries, versions, BCC and location data

Most field-decoding failures begin earlier than the field itself. This guide validates stream boundaries, unescaped bytes, checksum and header layout before interpreting a message body.

Read the guide