Spectrum Controls 2085sc-IF8U User Manual page 8

1-2 Chapter 1, Module Overview
User's Manual Pub. 0300305-01 Rev. A
The 2085sc-IF8u Expansion I/O module measures current, voltage,
thermocouple, and RTD and resistance signals. The module supports:
 Eight input channels.
 Current measurements. The module measures the channel input
current across a low-drift precision resistor. To measure the voltage
and convert the voltage to a current reading, you install an external
jumper between the current and voltage points (CI_X and VI_X) on
the terminal block.
 Direct voltage measurements. The low-drift precision resistor is not
used, and the channel accepts the voltage source directly.
 Open-wire detection for current measurement on the 4-20 mA range,
voltage, and thermocouple measurements.
 Direct thermocouple. In thermocouple mode, the thermocouple
measurements can be compensated with the reading from a single
Cold Junction Compensation (CJC) sensor placed in the center of the
terminal block. The module measures thermocouple and Cold
Junction Compensation sensor voltages, and converts the results to a
temperature reading.
 One Cold Junction Compensation profile (averaged and distributed)
is supplied.
 Resistance (direct Ohm).
 RTD types. The RTD and resistance measurements use a constant
current injected through the resistive load, measuring the voltage
across the resistance, and converting the voltage to a temperature or
resistance reading. RTD and resistance input types support 2- or 3-
wire resistance measurements.
 Four data formats.
 Four filter frequency setup.
Real-time Terminal Block temperature updating when the channel is

enabled.
 Range scaling of input data.
 Over or under range detection (from user-defined values).
 Channel bias adjustments for each channel.
 An option to disable open-wire detection for volt, millivolt, and
thermocouple measurements.
All inputs have fault tolerance and ESD protection to avoid damage to circuitry
on the board. The modules use 50 VAC working Reinforced Insulation between
the inputs and the backplane, and low-level (10 VDC) channel-to-channel
isolation.
The 2085sc-IF8u module uses a 24-bit Sigma-Delta analog-to-digital converter to
achieve a 16-bit resolution with ±10 V full scale ranges. The module digitally
converts and stores analog data from either the current or voltage input type.
Each input channel is individually configured via Rockwell-provided Connected
Component Workbench (CCW) software for the Micro850 family of PLC
controllers, and with the Module Configuration Converter utility from Spectrum
Controls, Inc.