Module status and input data, Chapter – Rockwell Automation 1771-OFE/B Analog Output Module User Manual User Manual
Page 51
Chapter
5
Publication 1771Ć6.5.30 - November 1998
Module Status and Input Data
In this chapter, you will read about:
For information on
See page
ReadingData from the Module . . . . . . . . .
5-1
Block transfer read (BTR) programming moves status and data from
the module to the processor’s data table in one I/O scan. The
processor user program initiates the request to transfer data from the
module to the processor.
The transferred words contain module status, channel status and
input data from the module. The maximum BTR data file length
required is five words.
Figure 5.1
Word Assignment for Block Transfer Read
Decimal Bit
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
Octal Bit
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
Word 1
Channel 1 DAC Input Data
2
Channel 2 DAC Input Data
3
Channel 3 DAC Input Data
4
Channel 4 DAC Input Data
5
Not
used
I/O
Reset
Reserved
Data Valid
Important: The user program that uses the read block transfer must
make sure that Bits 06 and 07 (the write enable and read
enable request bits) of the MCB are not set
simultaneously.
What This Chapter
Contains
Reading Data from the
Module