Preface
Preface
P–5
effective resolution – The amount of jitter (data variation) that typically
occurs in the data word due to the influence of the internal electrical noise in
the module.
filter frequency – The user–selectable first–notch frequency for the A/D
converter’s digital filter. The digital filter provides AC power line noise
rejection when the first notch is at 10 Hz or at the power line frequency.
full scale error (gain error) – The difference in slope between the actual and
ideal potentiometer or RTD transfer functions.
full scale range (FSR) – The difference between the maximum and
minimum specified analog RTD or resistive input values.
gain drift – The change in full scale transition voltage measured over the
operating temperature range of the module.
input data scaling –The data formats that you select to define the logical
increments of the channel data word. These may be scaled–for–PID, or
Engineering Units for RTD or potentiometer inputs, which are automatically
scaled. They may also be proportional counts, which you must calculate to
fit your application’s temperature or resistance resolution.
local configuration – A control system where all the chassis are located
within several feet of the processor and chassis–to–chassis communication is
via a 1746–C7 or 1746–C9 ribbon cable.
LSB (Least Significant Bit) – Refers to a data increment defined as the full
scale range divided by the resolution. The LSB represents the smallest value
within a string of bits.
multiplexer – A switching system that allows several input signals to share a
common A/D converter.
normal mode rejection (differential mode rejection) – A logarithmic
measure in dB, of a device’s ability to reject noise signals between or among
circuit signal conductors, but not between equipment grounding conductor or
signal reference structure and the signal conductors.
potentiometer (Pot) – A variable resistor that can be connected to the RTD
module.
remote configuration – A control system where the chassis can be located
several thousand feet from the processor chassis. Chassis communication is
via the 1747–SN Scanner and 1747–ASB Remote I/O Adapter.
resolution – The smallest detectable change in a measurement, typically
expressed in engineering units (e.g., 0.1
°
C) or as a number of bits. For
example, a 12–bit system has 4,096 possible output states. It can, therefore,
measure 1 part in 4096.
RTD (Resistance Temperature Detector) – A temperature sensing element
with 2, 3 or 4 lead wires. It uses the basic characteristic that electrical
Summary of Contents for SLC 500 1746-NR4
Page 1: ...User Manual SLC 500t RTD Resistance Input Module Cat No 1746 NR4 Allen Bradley AB Spares ...
Page 15: ...Preface P 8 Notes AB Spares ...
Page 37: ...Chapter 2 Quick Start 2 12 Notes AB Spares ...
Page 63: ...Chapter 4 Preliminary Operating Considerations 4 12 Notes AB Spares ...
Page 87: ...Chapter 5 Channel Configuration Data and Status 5 24 Notes AB Spares ...
Page 107: ...Chapter 7 Module Diagnostics and Troubleshooting 7 8 Notes AB Spares ...
Page 117: ...Chapter 8 Application Examples 8 10 Notes AB Spares ...
Page 123: ...Appendix A Specifications A 6 Notes AB Spares ...
Page 125: ...Appendix B RTD Standards B 2 Notes AB Spares ...