4-20 mA Current Output Transmitter for
Position or Rate from Quadrature Encoders
Transmits accurate position or rate from shaft encoders & linear encoders.
DIN Rail mounted, digitally programmable.

Standard Features Accepts low-level differential or single-ended 5V logic level outputs from a shaft encoder, linear encoder, incremental encoder or optical encoder. Isolated 4-20 mA, 0-20 mA or 0-10V transmitter outputs, selectable Programmable for position, angle or rate Quadrature count x1, x2 or x4 Combined pulse rate to 250 kHz Display refresh rate up to 25/s Zero channel input DIN rail mount package only 22.5 mm thick Plug-in screw-clamp connectors Easy setup with PC-based Instrument Setup Software 5V, 10V or 24V dc sensor excitation output, isolated Dual solid state relays for alarm or control, isolated RS232 or RS485 serial communications, isolated Universal AC power, 85-264 Vac Priced at only $235 (basic quadrature transmitter) Options: Low voltage power, 10-48 Vdc or 12-32 Vac

Description

The Laureate 4-20 mA output quadrature transmitter accepts the A & B quadrature encoder signals to provide an analog output that tracks that tracks position, length, angle, or rate. The A & B quadrature signals are 90º 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.

Signal conditioner board for Laureate Quadrature Position & Rate Transmitter 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.

Available for Total or Rate

With the Standard main board, the transmitter totalizes the quadrature counts and then scales the total in software for the output. A zero index Z signal can be added as a third input to the A & B signals. The analog output is generated by an ultra-linear 16-bit (65,536 step) digital-to-analog converter (DAC) for 0.02% output accuracy.
With the Extended main board, the transmitter can can 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.

Standard features of Model LTA-Q include:

Analog transmitter output, 16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
Serial communications, isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Laurel ASCII protocol.
Dual solid state relays for control or alarm, isolated. Rated 120 mA at 130 Vac or 170 Vdc.
Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
Universal AC power supply for 85-264 Vac.

Easy Quadrature Transmitter programming is via Laurel's Instrument Setup Software, which runs on a PC under MS Windows. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL04).

Specifications
Laureate 4-20 mA Transmitter for a Quadrature Encoder Input

Quadrature Inputs

Type
Transitions Monitored
Max Pulse Rate
Internal Counts
Position Error

Differential or single-ended quadrature
x1, x2 or x4
250 kHz at x1, 125 kHz at x2, 62.5 kHz at x4
-999999 to +999999
No error contributed by transmitter

Quadrature Position Mode

Zero Adjust
Span Adjust

-999999 to +999999
0 to ±999999

Quadrature Rate Mode

Conversion Technique
Output Update Rate
Gate time
Time Before Zero Output
Time Base Accuracy
Zero Adjust
Span Adjust

Inverse period
30 ms + 0-2 signal periods
Selectable 10 ms to 199.99 s
Selectable 10 ms to 199.99 s
Calibrated to ±2 ppm
-999999 to +999999
0 to ±999999

Analog Output

Output Levels
Compliance, 4-20 mA
Compliance, 0-10V
Output Resolution
Output Accuracy
Output Update Rate
Output Isolation

4-20 mA and 0-10 Vdc (selectable)
10V ( 0-500 ohm load )
2 mA ( 5 kOhm load )
16 bits (65,536 steps)
±0.05% of output span
25/sec max
250V rms working, 2.3 kV rms per 1 minute test

Sensor Excitation Output (standard)

Output Levels
Output Isolation

5V@100 mA, 10V@120 mA, 24V@50 mA (jumper selectable)
50V from signal ground

Dual Relay Output (standard)

Relay Type
Load Rating

Two solid state relays, SPST, normally open, Form A
130 mA at 140 Vac or 180 Vdc

Serial Communications (standard)

Signal Types
Data Rates
Output Isolation
Serial Protocols
Modbus Modes
Modbus Compliance
Digital Addressing

RS232 or RS485 (half or full duplex)
300, 600, 1200, 2400, 4800, 9600, 19200 baud
250V rms working, 2.3 kV rms per 1 min test
Modbus RTU, Modbus ASCII, Laurel ASCII
RTU or ASCII
Modbus over Serial Line Specification V1.0 (2002)
247 Modbus addresses.
Up to 32 devices on an RS485 line w/o a repeater.

Power Input

Standard Power
Low Power Option
Power Frequency
Power Isolation
Power Consumption

85-264 Vac or 90-300 Vdc (DC operation not UL approved)
10-48 Vdc or 12-32 Vac
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test
2W typical, 3W with max excitation output

Mechanical

Dimensions
Mounting
Electrical Connections

128 x 103 x 22.5 mm
35 mm rail per DIN EN 50022
Plug-in screw-clamp connectors

Environmental

Operating Temperature
Storage Temperature
Relative Humidity
Cooling Required

0°C to 55°C
-40°C to 85°C
95% at 40°C, non-condensing
Mount transmitters with ventilation holes at top and bottom.
Leave 6 mm (1/4") between transmitters, or force air with a fan.

Application Examples of Laureate Quadrature Meters & Transmitters
Using Quadrature for Cutting to Length
	Controlling the repetitive cutting of material to length is an excellent application of a Laureate quadrature transmitter or Laureate quadrature meter. The quadrature encoder shares the shaft of a sensing wheel, whose rotation corresponds to lineal displacement of material. The transmitter compares the displacement reading against setpoint information, and then uses its dual relays to first slow down and then cut the material.
Using Quadrature for X-Y Positioning
	Accurate X-Y position or rate can be obtained from two shaft encoders, which convert linear position to quadrature signals as a shaft turns. In addition to serving as a transmitter, each Laureate transmitter or meter can use its optional dual relay setpoint capability for closed loop control.
Using Quadrature to Monitor a Drilling Operation
	Quadrature can be used to track position and vertical drilling speed of the bit in an oil drilling operation. A shaft encoder is rotated by a cable that moves with the drilling shaft. In this application, the same encoder signal is applied to a Laureate quadrature transmitter for position, and to a second quadrature transmitter for rate. Both transmitters can send a 4-20 mA signal to a control room and be alarmed. In this application, quadrature provides much higher immunity to noise and jitter than a magnetic pickup.

Pinout
Laureate 4-20 mA Transmitter for Quadrature Encoder Input

Ordering Guide
Laureate 4-20 mA Transmitter for Quadrature Encoder Input
Click on the radio buttons to build a model number with pricing (shown below the Ordering Guide).

Quantity
Transmitter Type	LTA Laureate 4-20 mA Transmitter	$235
Main Board	6 Standard Main Board 8 Extended Main Board	NC $40
Main Board	With Standard Main Board: Scalable to ±999,999 to read out position, length or angle from shaft encoders. With Extended Main Board: Scalable to ±999,999 to read out bi-directional rate or position from shaft encoders (not simultaneously).
Power	0 Isolated 85-264 Vac 1 Isolated 12-32 Vac or 10-48 Vdc	NC $30
Relay Output	0 None 2 Isolated Dual Solid State Relays	NC NC
Input Type	QD Quadrature.	$30
Accessories	CBL04 RS-232 cable, TA to computer or USB adapter CBL02 USB to RS-232 cable adapter	$19 $39