For over 17 years, US communications and data acquisition supplier, Quatech has been designing and manufacturing boards for PC-based systems. At this year’s ISA Expo, held last month in New Orleans, the company announced some significant developments in radio telemetry for process control.
Quatech’s existing product lines included serial, parallel, analog and digital boards for PCMCIA, PCI , ISA and USB interfaces. With this latest development, the company has moved into the world of wireless telemetry. By building on its remote data acquisition and signal conditioning modules for serial networks, the QTM-8524 direct sequence spread spectrum (DSSS) RF modem modules take the system wireless.
The modules operate in the 2.4GHz ISM band and, as a wide-band spread spectrum system, can be used alongside other radio systems without any signal conflict so no operating license is necessary.
The modules use phase shift keying (PSK modulation and have a very low signal-to-noise ratio, making them ideal for use in factories and other high-noise environments. Additional advantages of the DSSS implementation are high throughput, and a noise-like signal that is particularly resistant to deliberate or accidental interception, demodulation and jamming.
QTM-8524 modules convert RF signals to serial RS-232 or RS-485 for communication with a PC or a serial network. They can be used to network two PCs, a PC and a PLC, or they can be used in conjunction with data acquisition modules to create a flexible, low-cost modular data acquisition and control system suiting a wide range of process and monitoring applications. Analog and digital I/O modules are available for voltage (V or mV) and current (mA) signals. Signal conditioning is provided for RTDs, thermocouples, and strain gages. Relay output and counter/timer modules round-out the series for complete system solutions.
The system has the ability to combine multiple modules operating at different baud rates, with different data formats, and at different frequencies (for wireless modules) into a single system controlled by a single PC via a standard serial port.
Also available are DDE servers, 32-bit Windows DLLs, ActiveX/OCX controls and a custom set of LabView Virtual Instruments.