Rockwell Automation 1756-OF8I ControlLogix Eight-channel Isolated Analog I/O Modules User Manual
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Rockwell Automation Publication 1756-UM540A-EN-P - May 2014
Appendix A
Isolated Analog I/O Module Tag Definitions
Ch[x].Overrange
BOOL
Indicates the channel data is above the absolute
maximum for this channel.
For example, when the channel operates in the
0…20 mA input range, the absolute maximum on the
channel is > 21.0 mA. If the input signal is 22 mA, this tag
is set to 1.
• 0 = Channel data is not above
the absolute minimum
• 1 = Channel data is above the
absolute minimum
Ch[x].LLAlarm
BOOL
Triggered when the I.Ch[x].Data tag value is less than the
C.Ch[x].LLAlarmLimit. tag value.
If latched, this tag remains set until unlatched or if the
I.Ch[x].Data tag value is within Deadband.
• 0 = Alarm is not triggered
• 1 = Alarm is triggered
Ch[x].LAlarm
BOOL
Triggered when the I.Ch[x].Data tag value is less than the
C.Ch[x].LAlarmLimit tag value.
If latched, this tag remains set until unlatched or if the
I.Ch[x].Data tag value is within Deadband.
• 0 = Alarm is not triggered
• 1 = Alarm is triggered
Ch[x].HAlarm
BOOL
Triggered when the I.Ch[x].Data tag value is greater than
the C.Ch[x].HAlarmLimit tag value.
If latched, this tag remains set until unlatched or if the
I.Ch[x].Data tag value is within Deadband.
• 0 = Alarm is not triggered
• 1 = Alarm is set
Ch[x].HHAlarm
BOOL
Triggered when the I.Ch[x].Data tag value is greater than
the C.Ch[x].HHAlarmLimit tag value.
If latched, this tag remains set until unlatched or if the
I.Ch[x].Data tag value is within Deadband.
• 0 = Alarm is not triggered
• 1 = Alarm is triggered
Ch[x].RateAlarm
BOOL
Triggered when the absolute change between
consecutive channel samples exceeds the
C.Ch[x].RateAlarmLimit tag value.
If latched, this tag remains set until it is unlatched.
• 0 = Alarm is not triggered
• 1 = Alarm is triggered
Ch[x].CalibrationFault
BOOL
Indicates the last attempted Calibration for this
channel failed.
This tag is cleared, that is, set to 0, when power is cycled
to the module.
• 0 = Calibration did not fail
• 1 = Calibration failed
Ch[x].Calibrating
BOOL
Indicates the channel is currently being calibrated.
• 0 = Channel is not being
calibrated
• 1 = Channel is being calibrated
Ch[x].CalGoodLowRef
BOOL
Indicates that a valid Low Reference signal has been
sampled on this channel.
• 0 = Valid Low Reference signal
has not been sampled on this
channel
• 1 = Valid Low Reference signal
has been sampled on this
channel
Ch[x].CalBadLowRef
BOOL
Indicates that an invalid Low Reference signal has been
sampled on this channel.
You must correct this condition to successfully calibrate
the module.
If calibration is aborted with an invalid Low Reference
signal, the I.Ch[x].CalibrationFault tag is set for this
channel until a successful calibration is performed.
• 0 = Invalid Low Reference signal
has not been sampled on this
channel
• 1 = Invalid Low Reference signal
has been sampled on this
channel
Table 21 - 1756-IF8I Module - Input Tags
Tag Name
Size
Definition
Valid Values