beautypg.com

Rockwell Automation 1769-IR6 Compact I/O 1769-IR6 RTD/Resistance Input Module User Manual

Page 112

background image

112

Rockwell Automation Publication 1769-UM005B-EN-P - March 2012

Glossary

data word

– A 16-bit integer that represents the value of the input channel.

The channel data word is valid only when the channel is enabled and there are
no channel errors. When the channel is disabled the channel data word is
cleared (0).

dB

– (decibel) A logarithmic measure of the ratio of two signal levels.

digital filter

– A low-pass filter incorporated into the A/D converter. The

digital filter provides very steep roll-off above it’s cut-off frequency, which
provides high frequency noise rejection.

effective resolution

– The number of bits in a channel configuration word

that do not vary due to noise.

excitation current

– A user-selectable current that the module sends through

the input device to produce an analog signal that the module can process and
convert to temperature (RTD) or resistance in ohms (resistance device).

filter

– A device that passes a signal or range of signals and eliminates all

others.

filter frequency

– The user-selectable frequency for a digital filter.

full-scale

– The magnitude of input over which normal operation is

permitted.

full-scale range

– The difference between the maximum and minimum

specified analog input values for a device.

gain drift

– Change in full-scale transition voltage measured over the

operating temperature range of the module.

input data scaling

– Data scaling that depends on the data format selected

for a channel configuration word. Scaling is selected to fit the temperature or
voltage resolution for your application.

input image

– The input from the module to the controller. The input image

contains the module data words and status bits.