Spectrum Controls 1746sc-INO4vi User Manual

Page 9

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Preface

v

Common mode voltage – The voltage difference between the negative
terminal and analog common during normal differential operation.

Common mode voltage range – The largest voltage difference allowed
between either the positive or negative terminal and analog common
during normal differential operation.

Configuration word – Contains the channel configuration information
needed by the module to configure and operate each channel. Information
is written to the configuration word through the logic supplied in your
ladder program.

D/A – Refers to digital-to-analog conversion. The conversion produces
an analog output signal whose magnitude is proportional to the digital
value.

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

Data scaling - The data format that you select to define the logical
increments of the channel data word.

Data word – A 16-bit integer that represents the value of the analog
output channel. The channel data word is valid only when the channel is
enabled and there are no channel errors.

Differential operation – The difference in voltage between a channel’s
positive and negative terminals.

Effective resolution – The number of bits in the channel data word that
do not vary due to noise.

Full-scale error (gain error) – The difference in slope between the
actual and ideal analog transfer functions.

Full-scale range (FSR) – The difference between the maximum and
minimum specified analog values.

Gain drift – The change in full-scale transition voltage measured over
the operating temperature range of the module.

LSB (least significant bit) – The bit that represents the smallest value
within a string of bits. The “weight” of this value is defined as the full-
scale range divided by the resolution.

Maximum differential voltage – The largest voltage difference allowed
between the negative terminal and positive terminal during normal
differential operation.

Module ID code – A unique number associated with each 1746 I/O
module. The code defines for the processor the type of I/O or specialty
module residing in a specific slot in the 1746 chassis.

Module update time – See channel update time.

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