Motorola V186 - Cell Phone - GSM System Planner Manual page 68

I/O Expansion
Expansion Module Power-up and Restart
The MCOM LED on the expansion module indicates the connection status between the
expansion module and the main CPU and expansion frame initialization progress.
The main CPU expects the expansion frames to complete the initialization within a
configurable period of time (60 seconds default). After this period of time elapses, the
main CPU will operate normally with the connected frames and their I/O modules. Any
expansion frame that has not completed initialization within that time (e.g. because it was
connected later to the RTU) will be ignored until the next main CPU restart.
Note that after the main CPU starts up, it waits for the expansion modules to complete the
initialization process. The wait time is derived from the number of expansion frames
configured in the RTU. After all the expansion frames have completed the initialization,
the main CPU will continue its system startup. The main CPU will wait 60 seconds
(default) for all expansion frames to connect.
Expansion Module during Run-Time
The expansion module constantly exchanges I/O data and status data with the main CPU,
using the Ethernet Micro-code Interface (EMI). The EMI enables the main CPU to be
updated by all the expansion modules every very short period of time via the expansion
Ethernet LAN. The main CPU constantly synchronizes the expansion module date and
time, and periodically polls the errors, pushbuttons and time tagged data from all the
connected expansion modules.
If the connection between the expansion module and the main CPU is lost (e.g. due to
main CPU restart, cable disconnection, etc.) for a configurable period of time (1 minute
default), the expansion module will restart and the initialization process will begin again.
After the expansion frames have initialized, it is possible to download to the RTU a user
program or other user defined files. After successful download, the main CPU
automatically updates each expansion module. Note that if the main CPU tries to
download a user program or other files to an expansion module during initialization, the
expansion module is restarted.
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