Specifications

i50 Manual (5.10)

Page 19

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6.4 Engine Running State

The i50 attempts to detect the vehicle engine running state to calculate engine running hours, drive

time, and idle time. The engine state is detected as follows (in order of precedence):

1) If OBD-II data is available, engine is running if RPM exceeds 300.

2) If any input is configured as Engine-On, engine is assumed to be on if the input is active.

3) If the Engine On Battery Voltage setting is non-zero, engine is assumed to be on when the

battery voltage exceeds this level.

4) Otherwise, IGN input is used. IGN high indicates engine is running.

6.5 Network

The i50 monitors all connected modems for network signal, and chooses the lowest cost option

available when sending data. For example, an i50 can be configured with both satellite and cellular

modems. While in cell coverage, all data will be sent through the cellular modem, but if coverage is

lost the i50 will automatically switch to the satellite modem. When cell coverage is regained the unit

will switch back immediately to the lower cost modem.

When no network is available, or the i50 has been configured to buffer reports, the outgoing packets

will be stored in memory for transmission at a later time. Up to 200 events or 2000 GPS positions can

be buffered at once. An internal backup battery keeps all buffered reports retained in memory if the

i50 is turned off.

6.6 Packet Size

Data packets will vary in size depending on the i50 settings and available data. Size will also depend

on which network is being used. The following list shows approximate payload length:

Standard GPS Report: 16 bytes

Advanced GPS Report: 21 bytes (basic information)

41 bytes (all options)

Basic Events: Add 1 byte

Status/Start/Stop Events: Add 51 bytes (without OBD-II)

Add 84 bytes (with OBD-II)

On top of these payloads, cellular and RF networks require a 3 byte Asset ID. Cellular packets will

also be embedded in UDP/IP datagrams, adding 28 bytes.

Lastly, the server will send ACK packets over cellular and RF networks to acknowledge receipt of the

data. These ACKs will add 4 bytes (32 including UDP cellular datagram).

Note: when the i50 has buffered multiple positions in memory, the overall packet size will be smaller.

For example, 19 standard GPS reports will fit into a single 250 byte packet. Buffering can be enabled

on a per-network basis using the i50 settings.