© Microhard Systems Inc.
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3.0 Hardware Description
3.4.2 MHX Development Board Connectors & Indicators
3.4.2.1 Front (Continued)
System Status LED (Green)
This LED is illuminated when the system is powered-up and core status is okay. This is the
only LED that is illuminated when the modem is in COMMAND MODE.
TX LED (Red)
When illuminated, this LED is indicating 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.
Table 3-6: LED Operation
MODE
LED STATUS
M/R/S
RX/SYNC
TX
RSSI 1,2,3
COMMAND
All
OFF
OFF
OFF
DATA
Master
ON while receiving valid
data
packets
from
Slaves and Repeaters in
the network
ON
1-3 ON in proportion to signal
strength received from Slaves
and Repeaters in the network
Fast Sync
Master
OFF
ON
Cycling with 300ms ON time
DATA - during
sync. acquisition
Repeater
OFF
OFF
Cycling with 300ms ON time
DATA - when
synchronized
Repeater ON for first portion of
hop interval
ON for second
portion of hop
interval
1-2 ON in proportion to signal
strength received from Slaves;
if Slaves silent for >2s,
Repeater will indicate RSSI
based on signal strength
received from Master
DATA - during
sync. acquisition
Slave
OFF
OFF
Cycling with 300ms ON time
DATA - when
synchronized
Slave
ON
ON
when
transmitting a
packet
1-3 ON in proportion to signal
strength
received
from
Repeater or Master with which
Slave communicates