Service manual

EXTERNAL SERIAL CONTROL PROTOCOL
B-8
April 2001
Part No. 001-9800-203
Radio Model:
Eight printable ASCII bytes indicating the
model identification. This is provided only
when power on is allowed.
Serial Number:
A variable length serial number that was sent in
the EVENT POWER ON REQUEST
message. This is sent by data and high tier
models, but not low or mid tier models.
B.4 POWER DOWN MODE
B.4.1 INTRODUCTION
The external device enters the Power Down mode
when it needs to disconnect or power off. The
subscriber logic controller also switches to this mode
when it needs to power down or force the external
device to shut down
The flowcharts of the various power-down events
are as follows:
Event Flowchart
Request Accepted Figure B-2
Request Denied Figure B-4
Broadcast Power Down Figure B-3
Addressed Power Off Figure B-5
B.4.2 MESSAGE FORMATS
EVENT POWER OFF REQUEST
Function
: This is a request from an External Device to
de-register and optionally power down the
subscriber unit or from the subscriber unit to an
external device to force a power down or discon-
nect. When the reason for power off is the power
switch or idle time out, the subscriber unit de-
registers the external unit and begins bus access
messages. The subscriber unit does not power
down. For any other reason, the subscriber unit
only de-registers the requesting device and other-
wise remains operational.
Origin
: External device
Format
:
Data:
Reason:
0x00 - Power switch
0x01 - Power down or idle time out
0x02 - Unit failure
0x03 - Disconnecting
EVENT POWER OFF
Function
: This message from the subscriber unit logic
board is used to tell the External Device if it can
power down. This opcode can also be used to force
a power down of the specified device/devices.
NOTE: Reception of an EVENT POWER OFF may
occur without a corresponding EVENT POWER OFF
REQUEST such as when the user presses the power
off button. It also may be a delayed power off as in the
case of ignition sense time out.
External Device Action
: Upon reception of a properly
addressed EVENT POWER OFF, if the External
Device requested this through a power off request or
the subscriber unit is powering down (see Action
field in message), the External device must power
down. If this is unsolicited, (a forced power-down)
the External Device must become non-functional
,
and move to its unregistered mode. The unit may
attempt registration again upon reception of an
INFO BUS ACCESS PERMITTED message.
Origin
: Subscriber unit logic board
Format
:
Opcode Reason
1 byte 1 byte
0x04
Opcode Action
1 byte 1 byte
0x05