Rockwell Automation Allen-Bradley 1769-IF4, User Manual

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Publication 1769-UM002B-EN-P - July 2005
Module Data, Status, and Channel Configuration for the Input Modules 3-3
1769-IF4 Input Data Values
Words 0 through 3 contain the converted analog input data from the field
device. The most significant bit (MSB) is the sign bit.
General Status Bits (S0 through S3)
Word 4, bits 0 through 3 contain the general operational status bits for input
channels 0 through 3. If set (1), these bits indicate an error associated with that
channel. The over- and under-range bits for channels 0 through 3 are logically
ORed to the appropriate general status bit.
Over-Range Flag Bits (O0 through O3)
Over-range bits for channels 3 through 0 are contained in word 5, bits 8, 10,
12, and 14. They apply to all input types. When set (1), this bit indicates input
signals beyond the normal operating range. However, the module continues to
convert analog data to the maximum full range value. The bit is automatically
reset (0) by the module when the over-range condition is cleared and the data
value is within the normal operating range.
Under-Range Flag Bits (U0 through U3)
Under-range bits for channels 3 through 0 are contained in word 5, bits 9, 11,
13, and 15. They apply to all input types. When set (1), this bit indicates input
signals below the normal operating range. It may also indicate an open circuit
condition, when the module is configured for the 4 to 20 mA range. However,
the module continues to convert analog data to the minimum full range value.
The bit is automatically reset (0) by the module when the under-range
condition is cleared and the data value is within the normal operating range.