Block transfer read format chapter summary – Rockwell Automation 1771-IFE , D17716.5.90 USER MNL. ANALOG INPUT Module User Manual

Page 40

Advertising
background image

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

Advertising