System Operation
POWER STATES
The R4 is designed to operate in 4 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 software
command. The system can then be awakened from either listed sleep/standby state by Wake-On-LAN. The
system can also be awakened from S3 or S4 with a USB input device such as a HID compliant keyboard or
mouse.
To be awakened from S3 or S4 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 8.1, Windows 7.
HIGH PERFORMANCE SERIAL COMMUNICATION PORTS
The R4 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 standard 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.
Features of the serial ports include:
•
16C954 buffered UARTs with 128-byte FIFOs
•
Software configurable clock prescaler and divisor supporting a wide range of baud rates
•
Supports 9-bit protocol framing
•
Each port supports data rates up to 921.6 kbps
•
All modem control signals implemented on RS-232 ports
•
RS-485 line termination, pull-up and pull-down resistors are selectable via dipswitch on Port 3
•
Automatic RS-485 enable/disable in hardware on Port 3
•
Uses Sealevel’s SeaCOM enhanced serial driver (Version 3.6.25 or newer)
SERIAL PORT SETUP
The R4 Serial Ports are assigned I/O addresses and IRQs by the COM Express module BIOS or by a “Plug-n-
Play” Operating System.
©Sealevel Systems, Inc.
R4 Manual
13
SL9260 06/2015
