ANALOG DEVICES 7B30 Service Manual

Isolated, Voltage or Current Input

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FEATURES

Interfaces, amplifies and filters unipolar and bipolar millivolt
and voltage inputs.

Provides a protected precision output of either +1 V to +5 V
or 0 V to +10 V.

A plug-in 250W current sensing resistor is provided to
measure a process current input.

All 7B30 series modules are mix-and-match and Hot
Swappable.

APPLICATIONS

Industrial signal conditioning
Industrial signal isolation
Industrial signal filtering

PRODUCT OVERVIEW

The 7B Series of signal conditioners feature small size, low cost
and a wide output voltage range for a variety of applications
including process control and factory-floor environments. The
single-channel 7B modules accept inputs from a range of
transducers and are fully rated over the extended -40

o

+85

C industrial temperature range. All 7B Series modules are
rated for a nominal power supply input of +24 VDC; and, for
maximum flexibility, they will accept supply voltages in the +14
VDC to +35 VDC range. The input modules, with the exception
of the 7B21, provide a high-level output voltage that is factory
configured for either the +1 V to +5 V or 0 V to +10 V range.
The 7B21 is a unity gain, isolated input module with an
input/output range of +10V. Output modules are available that
provide either isolated process current or isolated bipolar
voltage output. Model 7B39 converts either a +1 V to +5 V input
to a 4 to 20 mA output or a 0 V to +10 V input to a 0-20 mA
output. The input/output ranges of the 7B39 are factory
configured. The 7B22 is a unity gain module that provides an
isolated +10V output signal. All modules have a universal pin­out and may be readily hot-swapped under full power without
disrupting field wiring. Each module accepts analog transducer
signals and transfers them to a process control or factory data
collection system without the inherent noise, non-linearity, drift
and extraneous voltages which frequently accompany the
signals.

o

C to

7B30

FUNCTIONAL BLOCK DIAGRAM

Figure 1. 7B30 Functional Block Diagram

The modules feature a maximum nonlinearity of +0.02% and
are factory calibrated to guarantee a maximum accuracy
specification of +

The 7B Series offers up to 1500 V rms continuous common
mode voltage isolation and 120 V rms of field wiring input
protection. The power supplies necessary to drive each of the
individual module’s input circuitry are internally isolated,
enabling the 7B Series modules to offer true channel-to-channel
isolation of the input signals.

The modules directly accept analog signals from
thermocouples, RTDs, current loop powered transmitters, and
other process control signals. The 7B Series modules amplify,
linearize, isolate, protect and convert the transducer output
signals to standardized analog inputs for high-level analog I/O
subsystems. The 7B Series Subsystem consists of 19-inch rack­compatible hardware (model AC 1363), with universal
mounting backplane and a family of plug-in (up to 16 per
backplane) input and output signal conditioning modules. Four­, eight-, and sixteen-channel backplanes are available. Each
backplane incorporates screw terminals for easy power
connections and field wiring, and includes a 25-pin D-type
connector for interfacing the high-level single-ended voltage
outputs to the user’s equipment. Gold-plated sockets are
provided on each channel of the backplane to ensure the
reliability of each module’s electrical connection.

0.1%.

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Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

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GENERAL DESCRIPTION

The 7B30 is a single-channel signal conditioning module that
interfaces, amplifies and filters unipolar and bipolar milli-vilt
and voltage inputs and provides a protected precision output of
either +1 V to +5 V or 0V to +10 V.

To measure a process current input, a plug-in 250W current
sensing resistor, Model AC1391, may be installed directly on the
7B backplane, using available pin sockets. The external current
sense resistor allows the current loop to be maintained even
when the module is removed from the backplane. Model 7B30
features a nonlinearity of +
+

0.1% maximum (+0.01% typical). To accurately measure low
level signals in electrically noisy environments, 1500 V rms of
galvanic transformer-based isolation with a common mode
rejection (CMR) of 160 dB @ 50/60 Hz and a normal mode
rejection (NMR) of 60 dB @ 50/60 Hz are provided. Rated to
operate with a nominal +24 VDC supply, Model 7B30 is nix­and-match and hot-swappable with other 7B Series input
modules, so it can be inserted or removed from any socket in
the same backplane without disturbing system power.

The floating differential input of Model 7B30 is fully protected

0.02% maximum and an accuracy of

7B30

up to 120 V rms line voltage. A one-pole 3 Hz filter
preconditions the input signal prior to amplification by a low
drift input amplifier. Amplitude modulation is used to
implement transformer isolation (1500 V rms input-t-output
and power). Isolated front-end circuitry power is supplied by a
DC/DC converter. The output section contains a two-pole
output filter and subsequent buffer ensures that a low noise, low
impedance (<1Ω) signal is available at the output to drive loads
of 2 kΩ minimum.

Figure 2

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7B30 Models Available

Model Input Range Output Range

7B30-01-1

7B30-01-2

7B30-02-1

7B30-02-2

7B30-03-1

7B30-03-2

7B30-05-1

7B30-05-1

7B30-05-2

7B30-05-2

7B30-06-1

7B30-06-2

7B30-07-1

7B30-07-2

7B30-08-1

7B30-08-2

7B30

0 mV to +10 mV +1 V to +5 V

0 mV to +10 mV 0 V to +10 V

0 mV to +100 mV +1 V to +5 V

0 mV to +100 mV 0 V to +10 V

0 V to +1 V +1 V to +5 V

0 V to +1 V 0 V to +10 V

+1 V to +5 V +1 V to +5 V

+4 mA to +20 mA1 +1 V to +5 V

+1 V to +5 V 0 V to +10 V

0 mA to +20 mA1 0 V to +10 V

-10 mV to +10 mV +1 V to +5 V

-10 mV to +10 mV 0 V to +10 V

-100 mV to +100 mV +1 V to +5 V

-100 mV to +100 mV 0 V to +10 V

-1 V to +1 V +1 V to +5 V

-1 V to +1 V 0 V to +10 V

1

Models 7B30-05-1 and 7B30-05-2 may be used to measure a process current input by installing a 250 Ω current sensing resistor, such as Model AC1391, on the backplane. With

this resistor installed, the current loop is maintained even when the module is removed from the backplane.

7B30 Specifications
(typical @ +23°C ±5°C and V

Description Model 7B30

Standard Range ±10 mV to ±1 V (Refer to Model Table)

Custom Ranges Not Available*

Output Range Options (RL > 2 kΩ)

Initial @ +25°C ±0.01% Span (±0.1% Span, maximum)

Nonlinearity

Input Offset vs. Temperature ±0.5 µV/°C

Zero Suppression vs. Temperature ±0.005% (Vz)4/°C

Span vs. Temperature ±35 ppm/°C

Output Offset vs. Temperature ±0.002% Span/°C

3

±0.02% Span, maximum

= +24 V dc)

s

+1 V to +5 V or 0 V to +10 V

Range1

Accuracy2

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