Limit example – Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules User Manual
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110
Rockwell Automation Publication 1756-UM533C-EN-P - February 2011
Chapter 7
Configure the Modules with RSLogix 5000 Software
Limit Example
If your output controls a valve positioner that is configured to use Percent of
Stroke for engineering units, and you don't want the valve to be over 62% open at
any time for any reason, then you can enter 0 as the Low Clamp and 62 for High
Clamp. Even if a PIDE instruction calculates the valve should be open more to
achieve process Setpoint, the output module clamps it to 62% open.
Ramp in Run Mode
Check
• Enables ramping in Run mode.
• Ramping occurs between the current output level and any new output
value received.
• If ramping is enabled, the output only can change at the configured ramp
rate limit.
No
Ramp Rate
Enter a value from
9,999,9999 to
999,999,999,
default is 0.
• Defines the maximum rate of change an output can make in engineering
units/second.
• Serves as a trigger point for a Ramp Rate Limit alarm when the Ramp in
Run mode is selected.
• Can also be uses to ramp a user-defined value in Program or Fault mode.
• A non-editable copy of Ramp Rate is shown on the Output State tab.
No
Unlatch All
Click
• Unlatches all alarms.
• Is not available when the project is offline.
Yes
Unlatch
Click
• Unlatches the adjacent alarm condition.
• Is not available when the project is offline.
Yes
Disable All Alarms
Check
Disables all alarms for a channel.
No
Latch Limit Alarms
Check
Maintains the high and low limit alarms even after the condition ceases. The
high and low limit alarm is set if the requested output is beyond the clamp
limit (>High or
Click Unlatch to unlatch an alarm, or send a Common Industrial Protocol (
)
message using the MSG instruction.
No
Latch Rate Alarm
Check
When enabled, a Rate Alarm indication remains set, even when the alarm
condition returns to normal. This latch lets you maintain the alarm even after
the condition ceases. The alarm unlatches only with an explicit message
acknowledging the alarm.
No
Table 28 - Alarm Tab Parameters (Continued)
Parameter
Action
Notes
Available in
Hard Run
Mode?