Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual - Manual (Page 63)

5–3 Module Status and Input Data
Publication 1771ĆUM127B-EN-P - December 2002
Definition
Decimal Bit
(Octal Bit)
Word
Word 1 continued
Bit 13 (15)
Module alarm. This bit is set if there is an alarm bit set for one
or more channels. The input alarm bits are low, high alarm and
rate alarm. The output channel alarm bits are low and high
clamp, and the rate limit alarm.
Bit 14 (16)
Bad channel data. This bit is set if the module is in BCD mode
and one or more of the input data values sent in the last BTW
are not legal BCD values.
Bit 15 (17)
Powerup bit. This bit is set until a BTW with programming data
is received by the module.
Word 2 Always 8000 hexadecimal.
Word 3 Not used. Always 0
Inputs Only" and Output/Input" Block Transfer Read
Data Header
This following three-word header is used if the module only has
input channels, or if it contains
both input and output channels.
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 1 Unused = 0
CJC
Over
Range
CJC
Under
Range
3 Cold Junction Temperature; Units of 0.01 degrees C or 0.1 degrees F
The bit/word descriptions for the “inputs only” and “output/input”
header block are shown below.
Word
Decimal Bit
(Octal Bit)
Definition
Word 0
Bits 00Ć15
(00Ć17)
Always = 8800 hexadecimal
Bits 00Ć05 Not used
Word 1
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.