Rockwell Automation Allen-Bradley 1769-IF4, Руководство пользователя

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Publication 1769-UM002B-EN-P - July 2005
3-18 Module Data, Status, and Channel Configuration for the Input Modules
1769-IF8 Input Data File
The input data table lets you access analog input module read data for use in
the control program, via word and bit access. The data table structure is shown
in the table below. For each input module, slot x, words 0-7 in the input data
file contain the analog values of the inputs.
1769-IF8 Input Data Values
Words 0 through 7 contain the converted analog input data from the field
device. The most significant bit (MSB) is the sign bit, which is in two’s
complement format. (Nu indicates not used with the bit set to 0.)
General Status Bits (S0 through S7)
Word 9, bits 0 through 7 contain the general operational status bits for input
channels 0 through 7. If set (1), these bits indicate an error associated with that
channel. The over- and under-range bits and the high- and low-alarm bits for
channels 0 through 7 are logically ORed to the appropriate general status bit.
Low Alarm Flag Bits (L0 through L7)
Word 10, bits 3, 7, 11, and 15 and Word 11, bits 3, 7, 11, 15 contain the low
alarm flag bits for input channels 0 through 7. If set (1), these bits indicate the
input signal is outside the user-defined range. The module continues to
convert analog data to minimum full-range values. The bit is automatically
reset (0) when the low alarm condition clears, unless the channel’s alarm bits
are latched. If the channel’s alarm bits are latched, a set (1) low alarm flag bit
clears via the corresponding Clear Alarm Latch bit in your output data file.
Table 3.11 1769-IF8 Input Data Table
Wo
rd
Bit Position
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 SGN Analog Input Data Channel 0
1 SGN Analog Input Data Channel 1
2 SGN Analog Input Data Channel 2
3 SGN Analog Input Data Channel 3
4 SGN Analog Input Data Channel 4
5 SGN Analog Input Data Channel 5
6 SGN Analog Input Data Channel 6
7 SGN Analog Input Data Channel 7
8 Nu Time Stamp Value
9 Nu Nu Nu Nu Nu Nu Nu Nu S7 S6 S5 S4 S3 S2 S1 S0
10 L3 H3 U3 O3 L2 H2 U2 O2 L1 H1 U1 O1 L0 H0 U0 O0
11 L7 H7 U7 O7 L6 H6 U6 O6 L5 H5 U5 O5 L4 H4 U4 O4