Spectrum-controls 1756sc-CTR8 Manual de usuario descargar pdf (Pagina 54)

44 ControlLogix

™

Counter Module

Meter Proving

The 1756sc-CTR8 module provides a feature that allows the user to

perform meter proving functions. A typical meter proving application

would include two detector sensors that are located a fixed distance from

each other within a section of pipe used specifically for meter proving.

The operation does not disrupt the in situ flowmeter’s operation.

Detector #1

Detector #2

Displacer

Utilizing the external gate enable to start and stop count functions enables

the user to count pulses as fast as 65kHz to an accuracy of 1 count.

Here is an example wave form representing the start and stop transitions

on the external gate enable, and the associated pulses that the module

would accumulate: [Storage mode 3, store, reset, wait, start]

Flow Meter Input

External Channel Enable

1 2 3 4 NA

Given the above wave form, the module will begin counting the first

positive going input pulse after the external enable input goes low. The

module will accumulate 4 counts in the channel count register and stop

when the external enable input goes high.

1 2 ... 49 50 51 52 53 54 55 56 57 58 59 ... 73 74

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Spectrum-controls 1756sc-CTR8 Manual de usuario Pagina 54