Wireless data acquisition system
Description
The DR9011 wireless transmitter provides analog and contact closure data transmission to a companion DR9021 where the data is recovered. The analog data is recovered as two 4-20mA outputs and the switch data is provided by optically isolated NPN transistors outputs. The analog inputs available are dual channel DC voltage or currents, single channel RTD, or strain gauge bridge inputs. The bridge version provides 10VDC precision excitation for up to four 330 ohm bridges. For the single channel inputs, the two 4-20mA outputs are both proportional to the single input. The DR9011/DR9021 point to point system has a choice of 3 radio frequencies; 2 in the 915MHz ISM band and 1 in the 2.4GHz band. All use spread spectrum frequency hopping technology. Each RF module has a choice of 7 Hop sequences. This allows up to 21 systems to operate in the same locale without interfering with each other. With proper antennas and installation, the 915MHz units can function reliably over a 20 mile range.