Input status data – Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual User Manual

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Module Status and Input Data

Publication 1771ĆUM127B-EN-P - December 2002

Definition

Decimal Bit

(Octal Bit)

Word

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.

Word 1 continued

Bit 12 (14)

RTS timeout. This bit is set if a BTR was not requested of the

module within the RTS sample time.

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 a legal BCD value.

Bit 15 (17)

Powerup bit. This bit is set until a BTW with programming data

is received by the module.

Bit 00

Cold junction compensation (CJC) underrange bit. This bit is

set if the CJC temperature is below 0

Word 2

Bit 01

Cold junction compensation (CJC) overrange bit. This bit is set

if the CJC temperature is above 70

Bits 02Ć14

(02Ć16)

Not used. Always 0

Bit 15 (17)

Always = 1

Word 3

Bits 00Ć15

(00Ć17)

Cold junction temperature. Units of 0.01 degrees C or 0.1

degrees F. (0.1 degrees C or 1.0 degrees F in BCD.)

Input Status Data

Each input channel has two words associated with it. One word
provides underrange, overrange, low and high alarms, rate alarm,
bad program and bad calibration information to the processor. The
second word contains channel input data. These words would
immediately follow the header on modules containing only inputs, or
after the output channel words on modules containing both outputs
and inputs.

Word/Dec. Bit

Word/Octal Bit

Channel 1 Status

Unused = 0

Bad

Calib

Bad

Prog

Rate

Alarm

High

Alarm

Low

Alarm

Unused = 0

Over

Range

Under

Range

Channel 1 Input Data