Product_description: ['Model L20100DCV3 by Laurel Electronics is a DC voltmeter which includes a DC signal conditioner set to the -20.000 to +20.000V DC range, universal 85-264 Vac or 95-300 Vdc power, two 8A Form C contact relays, and five red 14.2 mm (0.56 inch) LED digits. Five voltage ranges from +/-200.00 mV to +/-600.0V and four current ranges from +/-2.0000 mA to +/-5.000A are jumper selectable. All signal ranges are factory calibrated with calibration factors stored in EEPROM on the signal conditioner board. This allows ranges and signal conditioner boards to be changed in the field without recalibrating the meter. Error is less than 0.01% of full scale +/-2 counts at read rates up to 60/sec. Such high read rates are ideal for peak and valley capture, accurate analog output, and fast relay response. Zero and span are programmable from 0 to +/-99999 counts. Custom scaling and the 200 mV range make the voltmeter ideal for use with current shunts. 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. A 5V, 10V and 24V transducer excitation output is standard. 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.'] (Page 1)