Rockwell Automation 1771-OFE/B Analog Output Module User Manual - Manual (Page 52)

5-2
Publication 1771Ć6.5.30 - November 1998
Table 5.A
Bit/Word Description for Block Transfer Read
Word
Decimal Bits
(Octal Bits)
Description
1
Bits 00Ć15
(00Ć17)
Channel 1 DAC input data.
2
Bits 00Ć15
(00Ć17)
Channel 2 DAC input data.
3
Bits 00Ć15
(00Ć17)
Channel 3 DAC input data.
4
Bits 00Ć15
(00Ć17)
Channel 4 DAC input data.
Bits 00Ć03
When set, indicate invalid channel data is sent to the module.
These bits are not reset until a correct write block transfer is
sent. Bit 00 corresponds to Channel 1, Bit 01 to Channel 2,
and so on.
5 Bits 04Ć13
(04Ć15)
Reserved
Bit 14 (16)
Is the I/O RESET bit. When set, it indicates that the processor
is in TEST or PROGRAM mode (i.e., block transfer data is not
being written to the module).
The first four words of the block transfer read show the actual 12 bits
of data sent to the module’s digital to analog converters (DACs).
The first four words in the block transfer read appear in 12-bit binary
format regardless of the module’s mode of operation (BCD or 12-bit
binary).
The fifth word contains the status of each DAC word; that is,
whether data is out of range or scaling is improperly programmed.
The fifth word also indicates that I/O RESET has been established
(when the processor is in the PROG/TEST or RUN mode).
In this chapter, you learned the meaning of the status data the module
sends to the processor.
ChapterSummary