Digital Acoustics ESBx-110 Especificaciones descargar pdf (Pagina 102)

Core Software Operation

ADDvantage-32 PLUS ● AC to DC Power Converter

3-22

3.10 FREQUENCY INPUTS

X*** Parameters Y*** Parameters A*** Parameters

X***:TACH 1 GRat Y***:TACH 1 TYPE A***:SPEED IN 1

X***:TACH 1 RDia Y***:TACH 2 TYPE A***:SPEED IN 2

X***:TACH 1 EPR

X***:TACH 1 ZERO

X***:TACH 2 GRat

X***:TACH 2 RDia

X***:TACH 2 EPR

X***:TACH 2 ZERO

Frequency inputs convert an incoming pulse train into an analog value by counting the

number of pulse edges and calibrating it into a user value. Counting the number of edges

allows for a more accurate representation of the incoming pulse train. The analog value

is then stored in the analog data table.

There are two methods used for counting the pulse train edges: the averaging method and

the direct count method. Configuring Y***:TACH 1 TYPE or Y***:TACH 2 TYPE

determines which method is used. Both methods measure one or two phase inputs and

one or two pulse edges.

3.10.1 AVERAGING METHOD (TWO PHASE, 1 PHASE 2X, 1 PHASE 1X)

When one of these options is selected for the TACH TYPE, the pulse train edges are

counted and averaged over an internal sample period. This averaging method allows for

smoother control but can lead to inaccuracies if the duty cycle of the pulse is not 50/50.

Selection of the 1 PHASE 1X (one edge) option eliminates these inaccuracies but

decreases the resolution. This method should be used when the frequency input is used

for speed feedback and the frequency being applied is fairly low. It should also be used

for feedback applications that have significant cyclical resonance on the feedback.

3.10.2 DIRECT COUNT METHOD (TWO PHASE-S, 1 PHASE-2XS, 1 PHASE-1XS)

If one of these options for TACH TYPE is selected, the exact number of edges that occur

in the same internal sample period are counted. This method leads to a more accurate

count of the pulse train input but is not quite as smooth as the above method. This

method should be used for all applications other than those stated for the averaging

method.

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Digital Acoustics ESBx-110 Especificaciones Pagina 102