©Sealevel Systems, Inc.
R2 Manual
12
SL9247 2/2017
System Operation
POWER BUTTON
The power button on the front of the computer can be used to turn the system on, shut the system down or
place the computer in sleep states S3 or S4 (depending on OS support and configuration). The power
button can also wake the system up from sleep states S3 or S4.
The power button has a 3 second hardware debounce/delay built in so accidental shutdown does not occur.
This 3 second delay is present at all times so the power button must be held for 3 seconds before system
power up, power down, sleep or wake occurs.
POWER STATES
The R2 is designed to operate in four Power States as defined by ACPI.
S0 – Fully powered and operational
S3 – Suspended to memory (known as sleep in Windows)
S4 – Suspended to disk (known as Hibernate in Windows)
S5 – Powered down in standby (Windows Shutdown)
The system can transition from S0 to any of the three listed standby states (S3, S4, or S5) by either software
command or the Power Button. The system can then be awoken from either listed sleep/standby state by
holding the Power Button for 3 seconds. The system can also be awoken from S3 or S4 with a USB input
device such as a HID compliant keyboard or mouse.
To be awoken from a standby state with a USB device, the device must be present when the
computer enters the sleep state and must remain connected for the duration of the sleep state.
These power states are supported by Windows 8, Windows 7, Windows Vista, and Windows XP.
RESET BUTTON
The reset button at BP1 (located near the USB Type A and RJ45 connectors) generates a system level reset
(CPU included). Hold for 1 second to activate.
HIGH PERFORMANCE SERIAL COMMUNICATION PORTS
The R2 provides three high speed serial communication ports supporting data rates up to 921.6 kbps. Ports
1 and 2 are RS-232 serial ports. Port 3 is an RS-485 port for communication with equipment up to 4000 ft.
away from the computer or in noisy environments. The RS-485 2-wire mode is optimized for “Multi-Drop” or
“Party-line” operations selecting data from multiple peripherals (as many as 32 unit load devices can be
connected on an RS-485 bus).
In RS-485 mode, our special auto-enable feature allows the RS-485 ports to be viewed by the operating
system as a COM: port. This allows the software application to utilize the serial port for RS-485
communication without the need to control the direction of data between the master and slave device. Our
on-board hardware automatically handles the RS-485 driver enable.
