© Microhard Systems Inc.
35
RSSI
TX RX
CONFIG
3.0 Hardware Description
Drawing 3-26:
Nano Motherboard Front View
3.5.3 Connectors and Indicators
3.5.3.1 Front
On the front of the Development Board is the DIAGNOSTIC port, CONFIG Button, and the
RSSI, TX and RX LED’s.
The
Diagnostic
port (RS232) is used for two
purposes:
•
online diagnostics and configuration at
115.2kbps.
•
firmware upgrades
CONFIG Button
Holding this button depressed while powering-up the modem will boot the unit into configura-
tion mode: the default serial interface (rear DE9, RS232) will be active and set to operate at
its default serial baud rate of 9600bps.
TX LED (Red)
When illuminated, this LED indicates that the modem is transmitting data over the air.
RX/SYNC LED (Green)
When illuminated, this LED indicates that the modem is synchronized and has received valid
packets.
Receive Signal Strength Indicator (RSSI) (3x Green)
As the received signal strength increases, starting with the furthest left, the number of active
RSSI LEDs increases. Signal strength is calculated based on the last four valid received
packets with correct CRC. RSSI is also reported in S123.
Drawing 3-27:
Nano Enclosed Front View
Signal
Name
PIN
#
Input or
Output
DCD
RXD
2
O
TXD
3
I
DTR
SG
5
DSR
RTS
CTS
Table 3-9: Diagnostic Port RS232 Pin Assignment
Refer to
Section
3.4.2.1 Table 3-6:
LED Operation
for
more information on
LED behavior.
