Rockwell Automation Allen-Bradley 1769-IF4, Руководство пользователя

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Publication 1769-UM002B-EN-P - July 2005
3-10 Module Data, Status, and Channel Configuration for the Input Modules
Input Data Selection Formats
This selection configures channels 0 through 3 to present analog data in any of
the following formats:
•
Raw/Proportional Data
•
Engineering Units
•
Scaled-for-PID
•
Percent Range
Raw/Proportional Data
The value presented to the controller is proportional to the selected input and
scaled into the maximum data range allowed by the bit resolution of the A/D
converter and filter selected. The full range for a ±10Vdc user input is -32767
to +32767. See Table 3.7 Valid Input Data on page 3-11.
Engineering Units
The module scales the analog input data to the actual current or voltage values
for the selected input range. The resolution of the engineering units is
dependent on the range selected and the filter selected. See Table 3.7 Valid
Input Data on page 3-11.
Scaled-for-PID
The value presented to the controller is a signed integer with zero representing
the lower user range and 16383 representing the upper user range.
Allen-Bradley controllers, such as the MicroLogix 1500, use this range in their
PID equations. The amount over and under user range (full scale range -410 to
16793) is also included. See Table 3.7 Valid Input Data on page 3-11.
Percent Range
The input data is presented as a percentage of the user range. For example, 0V
to 10V dc equals 0% to 100%.
See Table 3.7 on page 3-11.
TIP
The ±10V dc range does not support the percent user
range data format.