Nuts and Volts - November 2014

HIGH PERFORMANCE 4-20 mA OUTPUT ULTRASONIC

SENSOR

The new 4-20HR-MaxSonar-WR sensors from Maxbotix are high accuracy ultrasonic sensors featuring a

4-20 mA output.

These sensors are a low cost IP67 rated drop-in replacement for use with existing PLC/ process control systems. The sensors offer superior rejection of outside noise sources and feature speed of sound temperature compensation.

The 4-20HR-MaxSonar-WR sensors provide range information from 50 cm to 500 cm, and have a 1.6 mm resolution, an operational temperature range from - 40°C to + 65°C (- 40°F to +149°F), real time automatic calibration, a 200,000+ hours MTBF, an operational voltage range from 12V to 32V, and a low 20-40 mA average current requirement. The sensors function well with multiple sensors in the same location, and they are RoHS and CE compliant.

A six-pin screw terminal header is included to simplify system connections for quick installation in applications such as: tank level measurement; tide/water level monitoring; solar/battery powered applications; industrial automation; and outdoor vehicle detection.

The 4-20HR-MaxSonar-WR sensors (and previous IP67

MaxBotix sensors) are manufactured in a variety of packages for easy mounting in existing fittings. The sensors are available in M30x1.5; 1” BSPP; 1” NPTS; and

3/4” NPTS PVC pipe fittings. Pricing starts at $199.95 each and $134.37 in 100 unit quantities.

ALL-IN-ONE USB/SERIAL

CONTROLLER

Saelig Company, Inc., now has available the Prolific PL2303RA — an all-in-one IC that provides a convenient low chip count solution for connecting an RS-232 full-duplex asynchronous serial device to any USB-capable host. This on-chip solution with its built-in charge-pump RS-232 transceiver and widely compatible virtual COM port drivers, and compact and low power serial devices can be made USB-ready easily.

The PL2303RA integrates a high baud rate RS-232 transceiver that meets the EIA/TIA-232F and CCITT V. 28 communications interface specifications. The RS-232 transceiver is a three-transmitter/five-receiver design with a built-in high efficiency charge pump circuit. Adding external 1 µF capacitors provides the required bipolar output to the transmitters to deliver the correct RS-232 output voltage levels without requiring external active components. The PL2303RA operates at a very low power consumption with a guaranteed data rate up to 1,000 kbps, and also features an active-low shutdown indicator pin.

By taking advantage of USB bulk transfer mode, large data buffers, and automatic flow control, the PL2303RA is capable of achieving higher throughput than traditional UART (Universal Asynchronous Receiver Transmitter) ports. The flexible baud rate generator of the PL2303RA can be programmed to generate any data rate between 75 bps to 1 Mbps. It supports remote wake-up from any of its RS-232 input pin signals. Four general-purpose I/O pins are also available for use in product designs.