Wavenet Technology Pty Ltd. BM3800D Benutzerhandbuch

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Installation________________________________________________ Boomer-III User Manual & Integrator’s Guide 
 
Copyright Wavenet Technology © October 2003 
50 
BM310012WT04 
 
Power Down Sequence 
The host/terminal may request the modem to turn OFF by de-asserting 
the HOSTPWR _ON or by sending a specific NCL command across 
the serial interface. For the modem to turn OFF after an NCL request 
the HOSTPWR_ON signal must be de-asserted.  
Warning: The power supply rail must be maintained during a power 
down sequence or else memory may be corrupted. 
The soft shutdown process starts when the HOSTPWR_ON control 
line is de-asserted. The shutdown process consists of the modem first 
de-registering from the network and de-asserting the DCD line. Next, it 
saves the modem configuration and network channel information. The 
modem then de-asserts the DSR line, signalling the modem is no longer 
in a ready state. This process can take a few seconds to complete. 
At this point, the host/terminal can remove the power from the modem 
and still maintain most of the modem settings and last registered 
network channel. The modem can be left with power applied and 
HOSTPWR_ON de-asserted. 
The reset line HCRESET can be asserted at this time in preparation for 
the next power-up sequence. This is optional and is intended for 
rebooting the modem only. Resetting the modem causes a cold start 
and flushes the saved modem settings. 
The following diagram shows the sequence for these actions. 
Power-Down Timing Diagram 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Note: DSR and DCD are active low signals. 
HOSTPWR_ON 
DCD 
DSR 
Modem internal power control 
Modem Internal Power 
1
2
3
4
Modem software is 
Operational
Network Deregistration 
RF Protocol Requirement