3540 – PC/104 RS-232, RS-422, RS-485 (Software Selectable) Serial Interface February 1, 2015 Sealevel SystemsInc. — No Comments The 3540 is the first PC/104 serial interface module to provide four software-selectable RS-232, RS-422, or RS-485 ports. RS-232, RS-422, or RS-485 mode may be selected independently via software command for each of the four ports, eliminating the need for setting jumpers or DIP switches. The board is designed using the XR16C864 UART, which provides a 128-byte FIFO, 8 times larger than boards designed with 16C550 compatible parts. The larger buffers allow error free operation even in high-speed applications. In RS-485 mode the C4-104.ULTRA offers automatic control of the RS-485 driver enable for trouble free network master arbitration. Additionally, the C4-104.ULTRA allows RS-485 network termination, critical to robust multi-drop communication, to be selectively added to the circuit via a simple software command. Each port software selectable for RS-232, RS-422, or RS-48516C864 buffered UART with 128-byte FIFOsData rates to 921.6K bpsAutomatic RS-485 enable/disableTermination, pull-ups, and pull-down resistors for each port are software selectableRight-angle connector available for OEM opportunities, 40-pin vertical header connector standard About Sealevel SystemsInc. Sealevel Systems, Inc. provides innovative hardware and software products enabling computer connectivity and control. Since 1986, we have manufactured Serial and Digital I/O products to serve our customers' interface requirements. Whether you're looking for synchronous or asynchronous serial, analog or digital I/O, industrial computers or touchscreen HMI systems, Sealevel has a solution. Our commitment to customer satisfaction is expressed by our ISO 9001:2000 registration and the Lifetime Warranty that is standard with all Sealevel manufactured I/O products. Currently, we offer over 300 standard RS-232, RS-422, and RS-485 serial and digital I/O devices for multiple interfaces including USB, Ethernet, PCI, PC/104, PCMCIA, ISA, and serial converters. Our Relio® industrial computers and embedded I/O servers offer solid-state reliability and the highest degree of scalable I/O expansion. We have expanded our product line to include SeaI/O® data acquisition modules, SeaPAC® industrial touchscreen HMI systems, and OEM boards.