Figure 3 - Serial Connector (Looking At Back Of Modem); Table 9 - Reset Button Functions - red lion BT-6821-AT-AC User Manual

1.3.8.3 Serial Port (DB9)
The modem's serial port is an RS232 DCE, compliant with EIA-232 standard. The connector used is DB9 female and is
shown in the illustration below.
For further serial wiring information, refer to the
1.3.9 RESET button functions
Mode
Hard reset
Factory restore
FW upgrade
USB pass-through
Figure 3 – Serial connector (looking at back of modem)
Hardware Installation
Table 8 – Reset button functions
Pattern
Press and hold for less than 3
seconds
Press and hold between 3 and 10
seconds
RS232 LED flashes quickly
Press and hold between 10 and 15
seconds
WAN LED flashes quickly
Press and hold for longer than 15
seconds
Signal LED flashes quickly
section.
Description
Standard reboot
Overwrites user configuration with the default
factory settings
Puts the modem in advanced firmware
upgrade mode by restarting the modem and
running the bootloader only. Do not use this
mode unless instructed to by BlueTree
Technical Support.
Puts the modem in main pass-through mode
to the RF module, allowing CCT provisioning
and PST support. Do not use this mode unless
instructed to by BlueTree Technical Support.