Rockwell Automation 1771-IFE , D17716.5.90 USER MNL. ANALOG INPUT Module - Manual (Page 40)

Module Status and Input Data
Chapter 5
5-2
The bit/word description for the block transfer read of the Analog Input
Module is described below in Table 5.A.
Table 5.A
BTR Word Format for the Analog Input Module
Word
Decimal Bit
(Octal Bit)
Description
Bit 00
Power up bit is used by the module to tell the processor that it is alive
but not yet configured. It is a key element in the application program.
Bit 01
Out of range bit is sent to tell the processor that one or more
channels are either over or under range. 1
Word 1
Bit 02
Invalid scaling bit reports that the scaling is somehow invalid.
Usually, both values are equal or minimum is greater than maximum
when this bit comes on. Can also be an invalid filter value.
Bit 03
Real time sample fault bit. This bit is set if the module is configured for
RTS and a block transfer read has not occurred within the
user-programmed period.
Word 2
Bits 00-15
(00-17)
Individual underrange bits for each channel. Bit 00 for channel 1, bit
01 for channel 2, etc. 1 These bits are set (1) at approximately the input
range limits selected from Table 5.B.
Word 3
Bits 00-15
(00-17)
Individual overrange bits for each channel. Bit 00 for channel 1, bit
01 for channel 2, etc. 1 These bits are set (1) at approximately the
input range limits selected from Table 5.B.
Word 4
Bits 00-15
(00-17)
Polarity bits are set when input is less than zero. Bit 00 for channel
1, bit 01 for channel 2, etc.
Word 5 thru 20 Input values. Word 5 for channel 1, word 6 for channel 2, etc.
1 Attention: If an input terminal's voltage exceeds +14.25V as referenced to module common, channelĆtoĆchannel crosstalk can cause
invalid input readings and invalid underrange/overrange bits.
Table 5.B
Input Range Selection
Voltage input Current input 1
1 to 5V dc 4 to 20mA
0 to 5V dc 0 to 20mA 1
-5 to +5V dc -20 to +20mA 2
-10 to +10V dc 2
0 to 10V dc
1 Current input mode selected by configuration plug.
2 Configurable using bi-polar scaling.
In this chapter you learned the meaning of the status information that the
input module sends to the processor.
Block Transfer Read Format
Chapter Summary