User's Manual

Interface Specification Document Rev. -
Cellular Radio Module CRM4250/4200
Company Confidential
Standard Communications Corp. -26- November 20, 2000
7.0 CONTROL MESSAGE FLOW DIAGRAMS
7.1 Initial Power-up Sequence
Upon initial power-up, the unit will execute a basic self-test / initialization routine and,
upon successful completion, send out a 'Radio Power On' message. The normal
sequence is then to initialize the radio mode (Data, Voice, Diagnostic).
If you select the Voice or Data mode the unit will then attempt to locate cellular service
and, if available, will indicate such with a 'Service Available' message.
At this point the unit is ready for normal operation.
Note: Your must select one of the three modes upon power up, radio reset or upon
receiving the 45h command.
7.2 Power-down Sequence
Normal power-down sequence requires shutting down any call or other connection in
process before removing power from the unit.
7.3 Change Operating Mode
The operating mode of the radio can be changed at any time using the set Initialize
radio mode command (56h). Care should be taken to insure that any connection
established in one mode is terminated (or properly monitored) when changing to an
alternate mode.