© Microhard Systems Inc.
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4.0 Operating Modes
4.1
Command Mode
In this mode:
•
the Nano module is offline (data is not passing through the unit via it’s local data lines or RF
communications)
•
if installed in an MHX Development Board, the only LED illuminated will be the small green
LED at the top right of the front panel SERIAL DIAG (RJ45) port (this LED is connected to
the Nano Interface Card’s Pin 18: USR_1 System Status Indicator output. The Nano Mother-
board is not equipped with this LED.
•
the Nano’s configuration options (registers) may be viewed and modified
4.1.1 How to Enter Command Mode
Two methods are typically used to place the Nano - installed in a Development Board or in a Nano
Motherboard - into command mode:
1. Force to Command Mode
•
power off the Development Board or Motherboard assembly
•
connect a 9-pin straight-through serial cable from PC COM port to the rear RS-232 port
•
launch a terminal communications program (e.g. HyperTerminal) and configure for 9600bps,
8 data bits, No parity, 1 stop bit (8N1)
•
press and hold the CFG/CONFIG button (S1 on front of unit)
•
continue to press the CFG/CONFIG button and apply power to the modem
•
release the CFG/CONFIG button
•
observe the front of the MHX Development Board: only the small green LED should be illumi-
nated, indicating that the Nano is in Command Mode.
2. Escape from Data Mode
•
with the Nano ‘online’, connect a 9-pin straight-through serial cable from PC COM port to the
rear RS-232 port
•
launch a terminal communications program (e.g. HyperTerminal) and configure for the Nano’s
established serial baud rate parameters (PC & modem must match)
•
pause 1 second, type ‘+++’ (see Section 6.2, S1), pause 1 second: the monitor should show
the module response of ‘NO CARRIER OK’
•
the Nano is now in Command Mode (observe MHX Development Board’s front panel: only
the small green LED should be illuminated)