58
Rockwell Automation Publication 1756-UM540E-EN-P - December 2017
Chapter 3
1756-IF8I Isolated Analog Input Module
Fault and Status Reporting
The 1756-IF8I module multicasts fault and status data with channel data to the
owner and listening controllers. The data is returned via module tags that you can
monitor in your Logix Designer application.
With some exceptions, as noted in the following table, the 1756-IF8I module
provides the fault and data status in a channel-centric format.
The following table lists the fault and status tags for the 1756-IF8I module
available in the Logix Designer application.
Data Type
Tag Name
Triggering Event That Sets Tag
Fault
Fault
(1)
The owner-controller loses its connection to the module.
Ch[x].Fault
The channel data quality is bad.
Ch[x].Underrange
The channel data is beneath the absolute minimum for this channel.
Ch[x].Overrange
The channel data is above the absolute maximum for this channel.
Status
CIPSyncValid
(1)
Indicates whether the module is synchronized to a valid CIP Sync time master on the backplane.
CIPSyncTimeout
(1)
Indicates whether a valid time master on the backplane has timed out.
CIPSyncOffsetJump
(1)
Indicates a significant jump, that is, 1 ms or greater, in the CST and CIP Sync times sent from the Time Master to the
module. (The Time Master sends the CST and CIP Sync times to the module every second.)
When a significant jump occurs, this tag value becomes 1 but changes to 0 a second later unless another jump
occurred.
Ch[x].Uncertain
The channel data can be imperfect.
Ch[x].LLAlarm
The
I.Ch[x].Data
tag value is less than the
C.Ch[x].LLAlarmLimit
tag value, the
O.Ch[x].LLAlarmEn
tag is set and alarms
are enabled for the channel.
Ch[x].LAlarm
The
I.Ch[x].Data
tag value is less than the
C.Ch[x].LAlarmLimit
tag value, the
O.Ch[x].LAlarmEn
tag is set and alarms
are enabled for the channel.
Ch[x].HAlarm
The
I.Ch[x].Data
tag value is greater than the
C.Ch[x].HAlarmLimit
tag value, the
O.Ch[x].HAlarmEn
tag is set and
alarms are enabled for the channel.
Ch[x].HHAlarm
The
I.Ch[x].Data
tag value is greater than the
C.Ch[x].HHAlarmLimit
tag value, the
O.Ch[x].HHAlarmEn
tag is set and
alarms are enabled for the channel.
Ch[x].RateAlarm
The absolute change between consecutive channel samples exceeds the
C.Ch[x].RateAlarmLimit
tag value.
This alarm only applies to enabled Process alarms.
Ch[x].CalibrationFault
Channel is not calibrated or the last attempted Calibration for this channel failed.
Ch[x].Calibrating
The channel is currently being calibrated.
Ch[x].CalGoodLowRef
A valid Low Reference signal has been sampled on this channel.
Ch[x].CalBadLowRef
An invalid Low Reference signal has been sampled on this channel.
Ch[x].CalGoodHighRef
An valid High Reference signal has been sampled on this channel.
Ch[x].CalBadHighRef
An invalid High Reference signal has been sampled on this channel.
Ch[x].CalSuccessful
Calibration on this channel is complete and the Calibrating state has been exited.
Ch[x].RateOfChange
The change in channel data since last sample in Engineering Units/Second.
Ch[x].Data
The channel data in scaled Engineering Units.
Timestamp
(1)
A 64-bit Timestamp that indicates when all eight channels were last sampled in terms of CIP Sync time.
RollingTimestamp
(1)
16-bit timestamp that ‘rolls’ from 0…32,767 ms. Compatible with existing PID instruction to automatically calculate
sample deltas.
(1) This tag provides module-wide data and affects all channels simultaneously.
