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OPERATION
Page 5-4 SmartTach Operating Manual
Using Other Instruments with the Analog Output Signal
The Analog Output signal of the SmartTach generates a real-time analog
output voltage representation of Speed. This precision output can be
used to continuously send speed information to a test cell computer, data
acquisition system, strip-chart recorder, etc. This output voltage is
generated by a precision 12-bit digital-to-analog converter (absolute
output accuracy is ±0.002 volts).
To insure maximum measurement accuracy at the external instrument
end, it is recommended that the analog output signal be connected to a
device having a differential voltage input. The analog output signal is
isolated from power ground. It is also recommended that coaxial cable
be used for the connection to maximize noise immunity.
The maximum output voltage range is 0.00 to 10.00 volts. Maximum
current draw from the output should be limited to 10 milliamperes. The
exact scaling, offset, and output voltage range limits are programmable
through the configuration parameters. The update rate of this output is
also programmable. This allows the analog output to be tailored to the
requirements of the instrument receiving the signal.
A common use for the analog output is to display speed at a remote
location. This can easily be done by using a digital voltmeter for the
remote display.
Many data acquisition systems and strip chart recorders allow calibration
of their analog inputs to match the outputs of the devices to which they
are connected. The SmartTach has a special feature which allows for
easy calibration of this type of equipment.
Configuration parameter 35 is used to output a test voltage from the
Analog Output. This test voltage can be set in the range of 0.00 to +10.00
volts in 0.01 volt increments. In general, most instrumentation will require
calibration at the minimum and maximum values of the Analog Output
signal. Please refer to Chapter 4, Parameter 34 for further details.
Using Range Outputs
The SmartTach unit is equipped with three individually configurable Range
Outputs. Range Outputs are solid-state contact closures that can be
opened or closed based on user defined functionality. There are two pins