Dataq DI-720-EN, User Manual

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DI–720/DI–722/DI–730 Series User Manual
Accessories
89
DI-5B42 2-Wire Transmitter Interface Modules
Each DI-5B42 2-wire transmitter interface module provides a single channel which accepts a 4 to 20 mA process cur-
rent input and provides a st1 to +5V output signal (see block diagram). An is20VDC regulated
power supply is provided to power the current transmitter. This allows a 2-wire loop powered transmitter to be
directly connected to the DI-5B42 without requiring an external power supply. The regulated supply will provide a
n20VDC at a loop current of 4mA to 20mA.
The DI-5B42 will provide a 1500V isolation barrier for non-isolated 2-wire field transmitters. It can also be used
when additional isolation is required between an isolated 2-wire transmitter and the input stage of the control room
computer.
The voltage output is logic switch controlled, which allows these modules to share a common analog bus without the
requirement of external multiplexers.
The DI-5B 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.
A precision 20
Ω
current conversion resistor is supplied with the module. All field inputs are fully protected from
accidental connection of power-line voltages up to 240VAC. The module has a 3dB bandwidth of 100Hz. Signal fil-
tering is accomplished with a six-pole filter, with two poles on the field side of the isolation barrier, and the other four
on the computer side.
Ordering Information
MODEL INPUT RANGE OUTPUT RANGE
DI-5B42-01 4mA to 20mA +1V to +5V