Impulse SCM5B30_31 - Manual

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Isolated Analog Signal Conditioning Products SCM5B
SCM5B30/31
Analog Voltage Input Modules, Narrow Bandwidth
Description
Each SCM5B30 and SCM5B31 voltage input module provides a single channel
of analog input which is filtered, isolated, amplified, and converted to a high level
analog voltage output (Figure 1). This voltage output is logic-switch controlled,
allowing these modules to share a common analog bus without the requirement
of external multiplexers.
The SCM5B modules are designed with a completely isolated computer side
circuit which can be floated to ±50V from Power Common, pin 16. This complete
isolation means that no connection is required between I/O Common and Power
Common for proper operation of the output switch. If desired, the output switch
can be turned on continuously by simply connecting pin 22, the Read-Enable
pin, to I/O Common, pin 19.
Signal filtering is accomplished with a six-pole filter which provides 95dB
of normal-mode-rejection at 60Hz and 90dB at 50Hz. Two poles of this filter
are on the field side of the isolation barrier, and the other four are on the
computer side.
After the initial field-side filtering, the input signal is chopped by a proprietary
chopper circuit. Isolation is provided by transformer coupling, again using a
proprietary technique to suppress transmission of common mode spikes or
surges. The module is powered from +5VDC, ±5%.
A special input circuit on the SCM5B30 and SCM5B31 modules provides
protection against accidental connection of power-line voltages up to 240VAC.
Figure 1: SCM5B30/31 Block Diagram
▲
Features
• Accepts Millivolt and Voltage Level Signals
• High Level Voltage Outputs
• 1500Vrms Transformer Isolation
• ANSI/IEEE C37.90.1 Transient Protection
• Input Protected to 240VAC Continuous
• 160dB CMR
• 95dB NMR at 60Hz, 90dB at 50Hz
• ±0.03% Accuracy
• ±0.005% Linearity
• ±1µV/°C Drift
• CSA Certified, FM Approved, CE and ATEX
Compliant
• Mix and Match SCM5B Types on Backpanel