[mikehaldas]

Corrects the LPR event payload docs to match posts observed on LPR-IP4 firmware 5.3.1, and records where behaviour differs by firmware.

IPC Event Format (v1.x)

• Keepalive: says the interval is configurable (keepaliveTimeval, 30-120 s), with 90 s given only as an example setting. Adds the firmware 5.3.1 body (config 1.7 + messageType keepalive + deviceInfo). Keeps the <DeviceInfo> form, labelled as older firmware. Notes that some cameras send an empty body.
• New LPR sample in the real V1 shape: no sourceDataInfo, overview as listInfo item 0, plate item with vehicleDirect, vehicleListType, corner points, PlateConfidence count, numeric plateColor, carAttr, carRect, and string targetType car.
• Direction is approach / away (earlier text said leave). Documents the count-attribute scales and adds a "Confirmed on" column.
• temporaryList and expired-plate behaviour are marked as not yet confirmed.
• New Firmware Differences table: VEHICE vs VEHICLE by build, vehicleListType never sent on 5.1.x, and so on.
• dataTime follows the camera's date format. The declared base64 length isn't reliable. Type attribute names vary by firmware. Fixed the subscribeRelation / subscribeOption swap in the target-crop sample.

LPR application page

• IPC XML sample replaced with the real shape (test plate IB36NL).
• Event Data table: firmware-dependent smartType, vehicleDirect, PlateConfidence, IPC carAttr, corner points, and the overview location and size.
• Removed the claim that vehicle attributes are NVR-only, and fixed the "not VEHICLE" note.
• NVR groupName marked as not yet confirmed.

NVR Event Format (v2.0)

• Fixed the IPC-column rows for messageType and targetType.
• The heartbeat is described as configurable and not measured; the ~10 s figure is marked unconfirmed.
• The vehicle (LPR) section is marked not yet re-verified. Added a groupName row, also marked unconfirmed.

IPC HTTP POST Format (v2.1)

• Notes that saving a V2 row also enables the V1 sender, and that only V1-layout posts were received in testing. No V2.1 post body is documented yet.

httpPostV2 Data Types

• The keepalive interval is configurable, and the "empty body" observation is limited to that camera model.

examples/

• ipc-v1x/lpr.xml is rewritten in the observed shape.
• ipc-v1x/keepalive.xml now holds the firmware 5.3.1 form. The old form moved to keepalive-older-firmware.xml.
• The README rows were updated to match.

Sample values are placeholders: 192.0.2.100 (RFC 5737 documentation range), 00:00:00:00:00:00, SERIALNUMBER.