Omega Vehicle Security OM5-C manual OM5-DT, General Purpose Input Modules, with DC Excitation

OM5-DT

General Purpose Input Modules, with DC Excitation

FEATURES

●INTERFACES TO DC DISPLACEMENT TRANSDUCERS AND OTHER DEVICES REQUIRING A STABLE DC SUPPLY

●HIGH LEVEL VOLTAGE OUTPUTS

●1500Vrms TRANSFORMER ISOLATION

●ANSI/IEEE C37.90.1-1989 TRANSIENT PROTECTION

●INPUT PROTECTED TO 240VAC CONTINUOUS

●FULLY ISOLATED EXCITATION SUPPLY

●100dB CMR

●1KHz SIGNAL BANDWIDTH

●±0.10% ACCURACY

●±0.02% LINEARITY

●±20∝V/°C DRIFT

●CSA CERTIFIED, FM APPROVED, CE COMPLIANT

●MIX AND MATCH OM5 TYPES ON BACKPANEL

DESCRIPTION

Each OM5-DT general purpose input module provides a single channel of transducer input which is filtered, isolated, scaled, and converted to a high level analog voltage output (Figure 1). This voltage output is logic switch

controlled, which allows these modules to share a common analog bus without the requirement of external multiplexers.

The 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.

The OM5-DT can interface to devices which require a precision 10VDC excitation supply. The 1kHz bandwidth significantly reduces ripple and noise inherent in these devices.

Transducer excitation is provided from the module by a very stable 10V source. The excitation supply is fully isolated, allowing the amplifier inputs to operate over the full range of the excitation voltage. This feature offers significant flexibility in real world applications. Eight full scale input ranges are provided, from ±1V to ±10V, producing ±5V full scale output.

The input signal is processed through a pre-amplifier on the field side of the isolation barrier. This pre-amplifier has a gain-bandwidth product of 5MHz and is bandwidth limited to 1kHz. After amplification, 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%.

Special input circuits provide protection of the signal inputs and the isolated excitation supply up to 240VAC.

	+EXC		4		LPF	Isochopper™
									20
		4						LPF
	+In		6	Surge		Amplifier			VOUT
DC LVDT						Pat Pending
		3		Suppression
or Other			5	and					19
Transducer				Protection
							+V	–V	I/O Common
	–In
		2
						Isolated
			3
						Excitation	Isolated		22
	–EXC	1				Source			RD EN\
						Computer-Side
							Power
	Backpanel
	Term Block
				1
				NC
				2
				NC					17
				+V
					Isolated				+5V
								Power
				–V	Field-Side
								Oscillator
					Power				16
									Power
									Common

FIGURE 1. OM5-DT Block Diagram.

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