User Manual

Serial interface specification: Turning the radio OFF
Integrator’s Guide – RIM 801D OEM Radio Modem
24
modem to terminal link, will not be saved. The SDU will be lost when the
unit enters shutdown or is turned off.
A controlled shutdown is necessary to allow the RIM 801D to tell the
DataTAC network that it is off air. The following schematic offers a low-
power shutdown circuit, together with an example of using a 6-AA NiCad
rechargeable battery pack to power the RIM 801D.
Please note that in the following circuit, the signals marked Shutdown and
Turnoff are not connected to the RIM 801D radio modem, but to the
processor of the embedded system. If no processor is present, the Turnoff
line can be tied to the RIM 801D’s Turnon,andtheShutdown signal can be
tied to the RIM 801D’s ONI line.
The ON button forces the system to turn on. The processor then sets the SHUTDOWN line
high. When the button is released the system stays on.
The OFF button sends a request to the processor to shutdown. The processor will then
set the SHUTDOWN line low after the radio has been shutdown.
If no processor is present, the TURNOFF signal can be tied to TURNON and SHUTDOWN can
be tied to ONI of the RIM 801D radio.
Figure 6: Controlled Shutdown Using a Low-Power Battery Supply
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