DI-500/510 Series and DI-750/760 Series Hardware Manual
5B Modules
40
DI-5B47 Linearized Thermocouple Input Modules
DESCRIPTION
Each DI-5B47 thermocouple input module provides a single channel of thermocouple input which is filtered, iso-
lated, amplified, linearized and converted to a high level analog voltage output (see block diagram). This voltage out-
put 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.
The DI-5B47 can interface to eight industry standard thermocouple types: J, K, T, E, R, S, N, and B. Its correspond-
ing output signal operates over a 0 to +5V range. Each module is cold-junction compensated to correct for parasitic
thermocouples formed by the thermocouple wire and screw terminals on the mounting hardware. Upscale open ther-
mocouple detect is provided by an internal pull-up resistor. Downscale indication can be implemented by installing
an external 47MW resistor, ±20% tolerance, between screw terminals 1 and 3.
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 com-
puter 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 circuit in the input stage of the module provides protection against accidental connection of power-line
voltages up to 240VAC.
Ordering Information
MODEL
TYPE
INPUT RANGE
ACCURACY*
DI-5B47J-01
Type J
0°C to +760°C (+32°F to +1400°F)
±0.61°C
DI-5B47J-02
Type J
-100°C to +300°C (-148°F to +572°F)
±0.32°C
Isolation Barrier
+PWR
PWR
+IN
+OUT
IN
OUT
Power
Oscillator
+V
-V
+V
+
f
-Vf
s
s
Thermocouple
Surge Suppression
-Vref
and Protection
CJC
LPF
Isolated
Ambient
Temp.
Sensor
Field-Side
Power
Isolated
System-Side
Power
LPF
Iso-Chopper II
Amplifier
Pat. Pending
TM
1
2
3
4
6
7
8
EXC
Linearizer
Free Datasheet http://www.datasheet4u.com/
