Model LT81QD includes:
Model LT81VF4 DIN rail transmitter by Laurel Electronics has Quadrature input for position or rate, 4-20 mA or 0-10V analog output plus RS232 or RS485 I/O and dual relays. The model is configured for Extended main board and Low voltage power 10-48 Vdc or 12-30 Vac. It accepts A & B quadrature encoder signals to provide an analog output that tracks position, length, or angle. The A & B quadrature signals are 90 degrees out of phase, and their phase relationship determines whether up counts (+) or down counts (-) are produced.
One, two or four quadrature transitions may be counted at a maximum combined rate of 250 kHz and be scaled internally to ±999,999. counts. The input circuitry which may be jumpered for either single-ended input signals or for balanced line driver signals. Anti-jitter circuitry eliminates errors produced by vibration of the encoder. In the event of a power failure, the current total may be stored in non-volatile memory and can be used as the starting point for counting when power resumes. Power fail or zero index capabilities are alternate meter setup choices.
Use of the Extended main board allows the transmitter to be programmed to output either total or rate or rate. For example, the output can track the speed of a moving slab from the RPM of a roller. The update rate for rate is a programmed gate time + 30 ms + 0-2 pulse periods.
A zero index pulse, if available, is interpreted by the meter as indicating a zero reference for an integral number of revolutions of a rotary shaft encoder or the home position of a linear encoder. It is used by the meter for initializing and to correct for any cumulative pulse count errors. Special circuitry corrects for width of the zero index pulse.
LTM Series serial output transmitters send data via an isolated serial port, which is user configurable for RS232 or RS485 and full or half duplex operation. Three protocols are user selectable: Modbus RTU, Modbus ASCII, or Laurel ASCII. Modbus operation is fully compliant with Modbus Over Serial Line Specification V1.0 (2002). The Laurel ASCII protocol allows up to 31 Laureate devices to be addressed on the same RS485 data line. It is simpler than the Modbus protocol and is recommended when all devices are Laureates. It also allows use of Laurel Datalogging Software.
Standard features of Laureate transmitters include:
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