Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual - Manual (Page 51)

4–11 Configuring the Module
Publication 1771ĆUM127B-EN-P - December 2002
Reset Value
If the channel is programmed to go to a user-selectable reset value
upon I/O reset, the value is entered (in scaled units) into that
channel’s proper configuration word. The value entered must be
between the high and low absolute limits. If user-selectable resetting
is not chosen, this field should be set to 0.
Input channel programming includes:
• low and high scaling
• low and high alarming
• alarm deadband
• rate alarming
• alarm enable
• digital filtering
• thermocouple type
• RTD type
• 10 Ohm offset
Scaling
Scaling input channels is identical to scaling output channels. Refer
to “Output Channel Programming Features” on page 4–6.
Alarms
Each input channel has five alarm functions that provide status
indication through five associated status bits in the block transfer
read data returned by the module.
Input alarms let the user specify a range of “good” input values. If
the input value goes outside of this range, and the alarm enable bit is
set, the module will set the low or high alarm bit for that channel.
The alarm values are written to the module in the same units as the
scaling values, and must be within the absolute signal limits
specified in appendix A.
• Underrange - This bit is set if the input falls below the
minimum range for that specific input type. This alarm is
predefined and cannot be changed by the user. In current loop
inputs, this bit also indicates an open loop.
Input Channel
Programming Features