Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual - Manual (Page 62)

5–2 Module Status and Input Data
Publication 1771ĆUM127B-EN-P - December 2002
The block transfer read data format consists of an initial block
header which identifies the type of module (input, output, or
output/input), and groups of words that contain information on either
an input channel or an output channel.
Output channel words are configured immediately after the block
header. If the module contains both output and input channels, the
output channel words come first in the block transfer read data
format.
Outputs Only" Block Transfer Read Data Header
This header is used for modules with outputs only (such as cat. no.
1771-NOC and 1771-NOV).
Word/Dec. Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Word/Octal Bit 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
0 Constant = 8800 Hexadecimal
1
Power
up
Bad
Chan.
Data
Mod
Alarm
RTS
Time
out
I/O
Reset
Program
Verify
Mod
Fault
Bad
Prog
Bad
Struct
Unused = 0
2 Constant = 8000 Hexadecimal
3 Unused = 0
The bit/word descriptions for the “outputs only” header block are
shown below.
Word
Decimal Bit
(Octal Bit)
Definition
Word 0 Bits 00Ć15
(00Ć17)
Always 8800 Hexadecimal
Bit 00-05 Not used. Always 0
Bit 06
Bad structure. This bit is set if there is an error in the BTW
header.
Bit 07
Bad program. This bit is set if any of the module level
programming data is illegal.
Word 1 Bit 08 (10)
Module fault. This bit is set if any of the programming data sent
to the module in the most recent BTW was illegal, or if one or
more channels has the bad calibration bit set.
Bits 09Ć10
(11Ć12)
Program verify. Indicates the result of verify request.
00 = verify not requested;
10 = verify failed;
11 = verify succeeded
Bit 11 (13)
I/O reset. This bit is set whenever the I/O reset line on the
backplane is asserted.
Bit 12 (14)
RTS timeout. This bit is set if a BTR was not requested of the
module within the RTS sample time.
Block Transfer Read
Data Format