Impulse SCM7B21_30_31 - Manual

Isolated Process Control Signal Conditioning Products SCM7B
For information call 800-444-7644 66
SCM7B21/30/31
Isolated Analog Voltage Input Modules
Description
Each SCM7B21/30/31 voltage input module accepts one channel of analog
voltage input which is filtered, isolated, amplified, and converted to a high level
analog voltage for output to the process control system.
These modules incorporate a five-pole filtering approach to maximize both time
and frequency response by taking advantage of both Thomson (Bessel) and
Butterworth characteristics. One pole of the filter is on the field side of the isolation
barrier; four are on the process control system side.
After the initial field-side filtering, the input signal is chopped by a proprietary
chopper circuit and transferred across the transformer isolation barrier,
suppressing transmission of common mode spikes and surges. The signal is
then reconstructed and filtered for process control system output.
Modules accept a wide 14 - 35VDC power supply range (+24VDC nominal).
Their compact packages (2.13"x1.705"x0.605" max) save space and are ideal
for high channel density applications. They are designed for easy DIN rail
mounting using any of the “-DIN” backpanels.
Figure 1: SCM7B21/30/31 Block Diagram
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Features
• Accepts Millivolt and Voltage Level Signals
• Provides High Level Voltage Outputs
• 1500Vrms Transformer Isolation
• Accuracy, ±0.03% of Span Typical,
±0.1% Max
• ANSI/IEEE C37.90.1 Transient Protection
• Input Protected to 120Vrms Continuous
• Noise, 500µV Peak (5MHz), 250µV RMS
(100kHz)
• CMRR, up to 160dB
• NMR, up to 85dB
• Easy DIN Rail Mounting
• CSA Certified, FM Approved
• CE and ATEX Compliant