Laurel Electronics Digital Panel Meters L71220QD Extended Quadrature Meter for Position or Rate, Six Green LED Digits, Extended Capabilities, 10-48 Vdc Power, Two Isolated Analog Outputs

Digital Panel Meters Model L71220QD by Laurel Electronics is a quadrature input counter which accepts the A & B quadrature signals from linear encoders and shaft encoders to provide a highly accurate, scaled display of position, length, angle or speed in engineering units, such as ft, cm, degrees, or ft/sec. The A & B quadrature signals are 90° out of phase, and their phase relationship determines whether up counts (+) or down counts (-) are counted. The meter totalizes the counts and then scales the total in software for display and control. A zero index signal, or Z signal, may be added as a third input to the A & B signals as the home position. One, two or four transitions may be counted at a maximum combined rate of 250 kHz and be mathematically scaled for display in engineering units from -999,999 to +999,999. In the event of a power failure, the latest total may be stored in non-volatile memory and can be used as the starting point for counting when power resumes. Modular architecture provides a choice of power supply boards, relay boards for alarm or control, analog output boards, and communication boards. Available communication boards include RS232, RS485, USB and Ethernet. The Modbus protocol is fully supported as is the simpler Custom ASCII protocol. Power and all inputs and outputs are mutually isolated. The meter fits in a 1/8 DIN panel cutout (92 x 45 mm) and is protected to NEMA 4X (IP65) when panel mounted. It is certified to CE, RoHS, and ETL / UL standards.