SMART I/O User’s Manual
©1996 PEP Modular Computers GmbH
March 12, 1996
Page 5 - 29
5
Chapter 5 Analog Modules
5.2 SM-PT100
5.2.1 Introduction
The SM-PT100 is used for 2, 3 or 4-wire temperature measurement using
PT100 sensors driven by an on-board constant current source. Temperature
measurements between -200
°
C and + 850
°
C are possible with corrective
calibration for the two possible PT100 4-wire classes being provided in
driver software for OS-9 operation. A fast 16-bit delta-sigma A/D converter
ensures an absolute accuracy of 0.2
°
C.
5.2.2 Specifications
Isolation
1.0 kV Optoisolated from the system
Input
4 PT100 groups
4-wire connection supported
Open Sensor Detection
Self Calibration
Overvoltage Protection
Temperature Range
Temperature Drift
Conversion Time
Input Impedance
Resolution
Absolute Accuracy
Linearization
:
±
25V (power connected)
:
±
35V (power disconnected)
: -200
°
C to 850
°
C
: 1 LSB/
°
C (not compensated)
: typ. 125 ms, max. 500 ms
(depends on filter settings)
: 10 M
Ω
(min)
: 16-bit
:
±
0.2
°
C (sensor errors excluded)
: by software
EEPROM
256-bit serial EEPROM for Calibration Data
Front Panel
2 Red LEDs
Power Cons.
350mW (min.), 450mW (max.)
Temperature Range Standard (0
°
C to +70
°
C), Extended (-40
°
C to +85
°
C)
Module Weight
40g
ID Byte
$60, read by the SPI Interface