Pioneer 2TM - Manual (Page 28)

Specifications and Controls
below safe operating level of ~11 VDC. 10 , 11 Genpowerd running on the onboard Linux
system or ups.exe running under Windows, detects the change of state and initiates OS
shutdown after a short wait, during which the shutdown may be canceled by raising the
battery voltage, such as by attaching a charger.
Genpowerd monitors the HOST serial RI port on /dev/ttyS0. Windows’ ups.exe requires
a dedicated serial port—COM2 on current systems, and prefers to monitor the CTS line.
Consequently, we wire the onboard PC serial connector differently for Linux versus
Windows PC. Please consult the AROS chapters for more detail.
S AFETY AROS W ATCHDOGS
AROS contains a communications watchdog that will halt the robot’s motion if
communications between a PC client and the robot server are disrupted for a set time
interval, nominally two seconds (watchdog parameter). The robot will automatically
resume activity, including motion, as soon as communications are restored.
AROS also contains a stall monitor. If the drive exerts a PWM pulse that equals or
exceeds a configurable level and the wheels fail to turn (stallval), motor power is cut
off for a configurable amount of time (stallwait). The server software also notifies the
client which motor is stalled. When the stallwait time elapses, motor power
automatically switches back on and motion continues under server control.
There also is the LowBattery FLASH parameter that sets off an audible warning when the
batteries fall below a safe charge level. To avoid systems corruptions, the AROS servers
force a soft system shutdown, possibly including the onboard PC (Linux genpowerd or
Windows’ ups.exe), when the batteries fall below approximately 11 volts.
All these “failsafe” mechanisms help ensure that your robot will not cause damage or be
damaged during operation. You may reconfigure the various FLASH-based parameter
values to suit your application. See Chapter 7, Updating & Reconfiguring AROS, for
details.
10 RI and DSR on the HOST serial port are RS232 low during reset or when the controller is in Maintenance Mode.
11 AROS versions 1.5 and earlier raised the HOST serial port's DSR and RI to RS232-level high and lowered the RI
for low-power condition, which worked fine for Linux genpowerd, but was incompatible with Windows’ ups.
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