Overview

Applications

Much more than a USB to serial converter the USBCOM isolates the USB host from the uncertain ities of the target serial port. As well as the standard RS-232 connection the USBCOM is equipped with dual RS-485 ports which can be configured as a single full-duplex RS-422.

Real-world serial connections are just as likely to be non-standard in that the baud-rate, word format, handshake, or protocol. With it's on-board array processer emulating hardware serial ports the USBCOM is software configurable to tackle any serial communications task. Access to the configuration and debugging interface is via the host USB port using any standard ANSI Terminal emulator and entering the special control sequence to bypass the data channel.

On-board configuration software allows the user to select the operating parameters of each port as well as default action. Alternatively the customer may specify their own requirements or else program applications directly on the USBCOM computer using a keyboard and VGA display or via the USB serial port.

The on-board VGA and PS/2 port will emulate an ANSI terminal or can be used for diagnosing communications problems especially over RS-485 buses such as MODBUS.

• USB to Serial converter

• Networked Operator Terminal

• Multiprotocol Hub

• Application Specific Computer

• Visitor Information Terminals

OPERATION

CPU

Conventional CPUs are interrupt driven single cores with general-purpose peripheral circuits. The USBCOM is different in that it uses the Parallax Propeller chip which is comprised of eight 20MIP 32-bit CPUs integrated onto a single chip. These CPUs called COGs are capable of emulating hardware peripherals in software in a deterministic realtime manner as well as general processing. As all I/O is general-purpose the ports may be retasked to suit application-specific requirements.

VGA

The standard display mode for VGA is 128 characters by 64 lines which may be changed to a more conventional 80x25. Software emulates standard VT-100 ANSI mode as the VGA is used as a terminal console in conjunction with a keyboard.

USB

A standard type B connection makes connection to USB host devices such as PCs possible. The USB port appears as a communications class device and is assigned a COMPORT by most PC operating systems. The port can be connected at up to 2Mbits/sec full-duplex and is electrically isolated from the external ports.

PS/2

PS/2 interfaces include keyboards and mice as well as other HIDs common to PCs. Although the port IS labeled Keyboard it is totally under software control and in combination with the I2C bus that is tandemed onto the connector it is possible to run I2C or SPI devices straight from these ports.

POWER

The USBCOM draws it's power directly from the USB port and is fully USB 2.0 compliant.

RS232

The enduring method for connecting low-speed devices and implemented in the USBCOM. This port supports full-duplex operation with or without handshake and in any format. Two hardware handshake lines are available if needed in the form of RTS/CTS or these may also be used as a secondary RS-232 port.

RS485/422

The RS485 can run up to 2Mbits/sec or more, the format of which is totally under software control through serial port emulation by an element or more of the array processor. By selecting RS422 mode both RS485 ports appear as a single full-duplex RS422 port.

Current

100ma

Physical

78mm x 70mm x 15mm (WLH)

Weight

200g approx

USB

USB 2.0, CP2102 USB UART slave, Standard B connection

Case

1mm Steel, powder-coated

Environment

0'C to +70'C operating

MEMORY

64K bytes EEPROM

Standards

IEC 1010; AS/NZS 3548 EMI/EMC; C Tick compliant

VGA

32x16 to 128x64, 64 colors, mixed text and graphics

PS/2

Keyboard

CONNECTIONS