Table 1-1: Port descriptions
Port label
Function
Ethernet
Enables TCP/IP connections to the AL205R/AL205B. Possible uses include: remote
configuration of the AL205R/AL205B using the A2Control graphical user interface
(GUI), pulling logs of collected ALERT2 data, streaming ALERT2 decoded data to
other endpoints, and firmware updates.
SD card Stores logs of all received ALERT2 traffic and decoder operation.
Console
Micro USB port intended for use with the A2Control GUI, but is available as an
ALERT2 Binary API port. This port appears as a serial port when plugged into a
computer. Serial port settings are fixed at 115200 8,N,1. When the device is starting,
some diagnostic information may be displayed.
USB
USB host port supports plugging in a USB flash drive for copying logs from the
AL205R/AL205B, as well as firmware updates. To copy the ALERT2 logs from the
device, create a folder called decoder_output on the USB flash drive. If, and only if,
the device finds this folder, ALERT2 output will be synchronized to the folder. The
USB flash drive is also used to install a firmware update.
GPS
GPS antenna must be connected for proper time sync. GPS is required for the
AL205R. NTP can be used instead of GPS in a AL205B, but time will be less accurate
due to NTP jitter.
Serial 1
Serial port 1
RX Radio 4-pin connection for receive radio
TX Radio 5-pin connection for transmit radio
Serial 2
Serial port 2
Serial 3
Serial port 3
1.2 Power
The AL205R/AL205B requires an external DC power source. The AL205R/AL205B can accept inputs
ranging from 9 to 17 VDC, and includes reverse-polarity protection. Typical installations will
provide power using 12 VDC lead-acid batteries.
Once deployed in the field, the current drawn by the AL205R/AL205B depends on the frequency
of GPS clock synchronization cycles and the number of message transmissions. Typical
applications have an average current draw of less than 4 mA at 12 VDC, making the
AL205R / AL205B ALERT2 Repeater / Base
2
