Laurel-electronics QLS Quad Output 4-20 mA Current Loop - Datasheet Manuel d'utilisateur télécharger pdf (Page 1)

LAUREL

ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1

LAUREL

ELECTRONICS, INC.

QLS Quad Output 4-

20 mA Current Loop

Splitter / Retransmitter

Features

• Accepts a 4-20 mA, 1-5V, 0-5V or 0-10V input signal.

• Drives four (4) independent 4-20 mA outputs proportional to input

• Outputs can share a common ground

• Grounds of input and outputs can differ by up to ±10V

• Opening any output loop does not affect the other loops

• ±10% zero and span fine adjustments for each output loop

• Loop current test point for each output, where 200 mV = 20 mA

• Indicator LED for each connected output

• Powered by 85-264 Vac (Model QLS-1) or 10-48 Vdc (Model QLS-2)

• Powers a 2- or 3-wire input transmitter at 24V with up to 30 mA

• 22.5 mm (0.9") wide case snaps to 35 mm DIN rail

• Weighs only 159 g (5.6 oz)

Problems with Current Loop Loads in Series

Not so good: A single 4-20 mA loop from a sensor is connector to a panel meter, a control valve, a recorder and a PLC in series. If

the loop opens, all devices in the loop fail.

1. All devices in the loop cannot share a common ground, but

must be electrically floating. This is often not possible.

2. When any device in a loop is removed, fails or if a wiring fault

occurs, all other devices in the loop loose their 4-20 mA signal.

3. The transmitter voltage compliance limit may be exceeded,

since the voltage drops across loads in series are additive.

4. The 4-20 mA signal to each load device cannot be individually

adjusted for calibration purposes.

The QLS Loop Splitter / Retransmitter Solution

Much better: Four independent 4-20 mA loops with ±10V common mode isolation. If any of the output loops opens, only a single

device is affected. The output loops can share a common ground.

1. Up to four (4) independently adjustable 4-20 mA outputs are

generated from a single input, which can be 4-20 mA, 1-5V,

0-5V or 0-10V, as selected by jumpers.

2. If any device in an output loop is removed from a loop or fails,

or if a wiring fault occurs in any loop, the other loops continue

to operate properly.

3. The outputs can share a common ground. The input and

outputs are mutually isolated to ±10V by means of active

circuitry to accommodate differences in local grounds with

normal industrial grounding practices.

4. Each loop only drives a single load, thus avoiding voltage

compliance problems.

5. ±10% of zero and span adjustment are provided for each out-

put loop to allow for independent loop calibration.

6. Diagnostics for each output loop are provided by a yellow LED

lamp to indicate loop continuity and by a test point across a

10Ω series resistor, where 200 mV corresponds to 20 mA. The

test point allows a multimeter to measure the loop current

without breaking the loop.

7. Power for the loop splitter can be 85-264 Vac (Model QLS-1)

or low voltage 10-48 Vdc or 12-32 Vac (Model QLS-2). An

excitation output is provided on the signal input side to a drive

a 2- or 3-wire transmitter at 24 Vdc and up to 30 mA.

1 2 3

Résumé du contenu

Page 1 - Features

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1 LAUREL ELECTRONICS, I

Page 2 - Ordering Guide

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 2 Specifications Signal

Page 3 - QLS Safe Operation

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 3 QLS Theory of Operatio

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Laurel-electronics QLS Quad Output 4-20 mA Current Loop - Datasheet Manuel d'utilisateur Page 1

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Laurel-electronics QLS Quad Output 4-20 mA Current Loop - Datasheet Manuel d'utilisateur Page 1

Naviguer en ligne ou télécharger Manuel d'utilisateur pour Matériel Laurel-electronics QLS Quad Output 4-20 mA Current Loop - Datasheet. Laurel Electronics QLS Quad Output 4-20 mA Current Loop - Datasheet User Manual Manuel d'utilisatio

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