7B30 Isolated, Voltage or Current Input

Introduction

7b30-01-1The 7B30 is a single-channel signal conditioning module that interfaces, amplifies and filters unipolar and bipolar millivolt and voltage inputs and provides a protected precision output of either +1 V to +5 V or 0 V to +10 V. To measure a process current input, a plug-in 250 Ω 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 ±0.02% maximum and an accuracy 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 V DC supply, Model 7B30 is mix-and-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.

Inside the 7B30 Series Module

The floating differential input of Model 7B30 is fully protected 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-to-output and power). Isolated front-end circuitry power is supplied by a DC/DC converter. The output section contains a two-pole low pass filter (-3 dB @ 3Hz), a buffer amplifier and a power oscillator. The two-pole output filter and subsequent buffer ensures that a low noise, low impedance (<1 Ω) signal is available at the output to drive loads of 2 kΩ minimum.



Input and Output Ranges


 7B30 Functional Block Diagram

Figure 1. 7B30 Functional Block Diagram 


7B30 Input Field Connections


Figure 2. 7B30 Input Field Connections


Input Types  Output Options
±10 mV to ±1 V
0 to 20 mA
4 mA to 20 mA 
+1 V to +5 V
0 V to +10 V 


View and Order Models

  Model 
Input Range
Output Range 
Order Now  7B30-01-1 0 mV to +10 mV
+1 V to +5 V
Order Now 7B30-02-1  0 mV to +100 mV +1 V to +5 V 
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7B30-02-2  0 mV to +100 mV   0 V to +10 V
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7B30-03-1  0 V to +1 V +1 V to +5 V
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7B30-03-2  0 V to +1 V   0 V to +10 V 
Order Now  7B30-05-1  +1 V to +5 V +1 V to +5 V
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7B30-05-1 
+4 mA to +20 mA1
+1 V to +5 V
Order Now 7B30-05-2 +1 V to +5 V  0 V to +10 V 
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7B30-05-2 0 mA to +20 mA1  0 V to +10 V 
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7B30-06-1  -10 mV to +10 mV +1 V to +5 V
Order Now 7B30-06-2  -10 mV to +10 mV  0 V to +10 V
Order Now 7B30-07-1 -100 mV to +100 mV +1 V to +5 V 
Order Now 7B30-07-2  -100 mV to +100 mV  0 V to +10 V 
Order Now  7B30-08-1  -1 V to +1 V
+1 V to +5 V 
Order Now  7B30-08-2  -1 V to +1 V   0 V to +10 V

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.

Specifications

7B30 Specifications
(typical @ +23°C ±5°C and Vs = +24 V dc)

 Description
Model 7B30 
Range1
Standard Ranges ±10 mV to ±1 V (Refer to Model Table)
Custom Ranges Not Available*
Output Range Options (RL > 2 kΩ)
+1 V to +5 V or 0 V to +10 V
 Accuracy2
Initial @ +25°
±0.01% Span (±0.1% Span, maximum)
Nonlinearity3  ±0.02% Span, maximum
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  ±0.001% Span/°C
Input Bias Current  ±1 nA
 Input Resistance
Power ON
2MQ
Power OFF 30 kΩ, minimum
 Output Noise
5 MHz Bandwidth  6 mV peak
10 Hz to 100 kHz Bandwidth
0.4 mV rms
0.1 Hz to 10 Hz Bandwidth
0.6 µV peak
Bandwidth, -3 dB 3 Hz
Output Rise Time, 10% to 90% Span
150 ms
Common-Mode Voltage (CMV) 
Input-to-Output and Power
 1500 V rms, continuous
Common-Mode Rejection (CMR) 
Output-to-Input and Power @ 50/60 Hz
160 dB
Normal Mode Rejection @ 50/60 Hz
60 dB
Input Protection 120 V rms, continuous±35 V dc, continuous
Input Transient Protection ANSI/IEEE C376.90.1-1989
IEEE-STD 472
IEC 255-4, Class II
Output Resistance < 1 Ω
Output Protection Continuous Short to Ground 
 Power Supply
Voltage Range, Operating +14 V dc to +35 V dc
Current
+25 mA, maximum
Sensitivity
±0.0001%/% of Vs
Mechanical Dimensions 1.663" x 2.11" x 0.563
(42.24 mm x 53.6 mm x 14.3 mm)
Weight 60 grams
 Environmental
Temperature Range
Operating -40°C to +85°C
Storage -40°C to +85°C
Relative Humidity, 24 hours
 0 to 90% @ +60°C noncondensing
ESD Sensitivity
IEC 801-2, Level 2
RFI Susceptibility ±0.5% Span error @ 400 MHz, 5 Watt, 3 ft

Warm-up time required to meet specifications is approximately 10 minutes.
* Contact factory for OEM requirements.
1 Model 7B30 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, the current loop is maintained even when the 7B30 module is removed form the backplane.
2 Includes the combined effects of repeatability, hysteresis, and nonlinearity.
3 Nonlinearity is calculated using best-fit straight line method.
4 Vz is the nominal input voltage that results in a 0 V output.
Specifications subject to change without notice.