March 28, 2012

PLC Programming

Serial port connection to PLCs Programmable Logic Controllers (PLCs) are a specialized variety of computer typically used for controlling machinery on assembly lines and other systems needing mechanical and electrical robustness. They provide industrial-grade levels of immunity to electrical noise, precisely deterministic timing, and the ability to operate in a wide range of temperatures. They are intended to provide numerous inputs and outputs and are used to replace older systems of relays. switches, and timers. One major advantage of PLCs […]
March 22, 2012

PCIe Riser Cards

In a server room, space is at a premium. As a consequence, the hardware is placed in racks of a standardized width and height, with a standardized spacing between mounting points along the racks’ vertical mounting rails. What has evolved are computers designed with correspondingly specific heights and width/s, to fit this storage and mounting system. The basic unit of height (called a “u”), is 1.75 inches vertically, and a standard rack is 42u high, just over 6 feet. Logically […]
March 19, 2012

Photo Printing Kiosk

Kodak photo kiosk When Kodak was designing its photo kiosks it found the need for numerous input and output interfaces, as the kiosks were equipped with variety of card slots, printers, and other I/O. In one kiosk variant or another, they included CompactFlash™, SD/SDHC/SDXC™, microSD, Memory Stick, Mini SD, xD-Picture Card™/SCM, MS DUO, SmartMedia™, and MultiMedia/RSMMC card readers; IrDA and Bluetooth™ wireless interfaces; USB; CD/DVD and floppy drives; a credit card reader, a scanner, and one or two printers. With […]
March 2, 2012

Raspberry Pi serial interfacing

The Raspberry Pi, the single-board computer that has been causing so much excitement lately, has actually got two serial ports. One is a “mini-uart” with interfacing built into the Raspberry Pi’s GPIO (General Purpose Input-Output) interface. The GPIO interface is a pin header, and the relevant serial port pins are as shown: Raspberry Pi mini UART GPIO pins   The Raspberry Pi Quick Start Guide from element 14 describes the process in simple terms: Serial connection The Serial Port is […]