Pepper Computer RS232, RS485 user manual SM-PT100, Introduction

Chapter 5 Analog Modules SMART I/O User’s Manual

5.2SM-PT100

5.2.1Introduction

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
	4 PT100 groups
	4-wire connection supported
	Open Sensor Detection
	Self Calibration	: ± 25V (power connected)
	Overvoltage Protection
		: ± 35V (power disconnected)
Input	Temperature Range	: -200°C to 850°C
	Temperature Drift	: 1 LSB/°C (not compensated)
	Conversion Time	: typ. 125 ms, max. 500 ms
		(depends on filter settings)
	Input Impedance	: 10 MΩ (min)
	Resolution	: 16-bit
	Absolute Accuracy	: ± 0.2°C (sensor errors excluded)
	Linearization	: 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

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March 12, 1996 ©1996 PEP Modular Computers GmbH Page 5 - 29