LT81FR Laurel Electronics LT Transmitter Part Number LT81FR Transmitter for Frequency, Rate, Total or Timing, Extended Capabilities, 4-20 mA Analog and RS232/RS485 Outputs, Dual 120 mA Relays, 10-48 Vdc Power

LT Transmitter Part Number LT81FR by Laurel Electronics is a programmable digital counter transmitter with a dual channel pulse input signal conditioner. Standard features include a user scalable 4-20 mA, 0-10V or +/-10V analog output, Extended capabilities, RS232 or RS485 data I/O, and two 120 mA solid state relays. Two channels A and B can be individually configured to display frequency from 0.005 Hz to 1 MHz, rate in engineering units, raw or scaled totals, and process times from 1 microsecond to 999999 hours. The counter determines frequency with quartz crystal accuracy by timing an integral number of periods over a specified gate time, and then taking the inverse of period. Rate is obtained by multiplying the input by a scale factor. AC line frequency may be accurately measured to 50.0000 or 60.0000 Hz in a few line cycles. Each channel (A or B) may be independently set up and scaled to count up from zero (or other value) to a preset limit, or to count down from a preset value to zero (or other limit). The FR dual-channel signal conditioner board accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from 12 mV to 250 Vac. A built-in isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors. The Modbus protocol is fully supported for data transmission as is the simpler Custom ASCII protocol. Power and all inputs and outputs are mutually isolated. The transmitter snaps onto a 35 mm DIN rail and is only 22.5 mm (0.89 inch) thick. It is certified to CE, RoHS, and ETL / UL standards.