Alarms Tab - 1794-IJ2, 1794-IJ2I, 1797-IJ2

Use this tab to set values for 1794-IJ2, 1794-IJ2I, or 1797-IJ2 alarming. On this tab, you can specify the following items on each channel:
  • Select or unselect startup mode.
  • Set a Missing Pulse Multiplier to modify the Minimum Frequency Sample Time for a channel.
  • Set a Missing Pulse Delay Multiplier to identify the number of Minimum Frequency Sampling Times allowed before generating an alarm.
  • Set the number of Pulses to Terminate Sampling and allow frequency calculation to begin (for the 1797-IJ2 you can use an alternate set of values for Pulses to Terminate Sampling).
  • Set the mode to use if a wire off or missing pulse detection results.
  • Set the module to detect a wire off condition on the frequency input.
  • Set the module to detect a wire off condition on the gate input.
    Tip:
    The module configuration information is stored in the
    module
    A device, typically an I/O device, that communicates with the controller. The controller, a particular 1756-IB16I or a PanelView are all considered modules.
    controller and the controller configures the module.
    controller
    A device that controls machines or processes elements (for example, a programmable controller or relay panel).
Parameters
Channel
Select the channel for which to set alarm values.
Startup Mode
Defeats any alarms from being generated for a time equal to 2 seconds plus the product of Missing Pulse Delay Multiplier and Minimum Frequency Sample Time. This is used primarily in a startup environment where you may wish a long delay before generating an alarm. Available options are Checked (Startup Mode – defeat the Missing Pulse Multiplier) or Unchecked (normal Run mode). By default this check box is unchecked.
Missing Pulse Multiplier
Modifies the Minimum Frequency Sample Time to allow the frequency bandwidth to be more closely adjusted to the value needed to report the proper frequency and report a missing pulse more quickly. The values are None (default), 2, 8, and 32.
Missing Pulse Delay Multiplier
Identifies the number of Minimum Frequency Sampling Times, after which an alarm is generated. The alarm is generated after the sample periods plus a 2 second delay. The values are None (default), 2, 8, and 32.
Pulses to Terminate Sampling
Lets you calculate frequency as soon as a specified number of input pulses have occurred, instead of waiting for the full Minimum Frequency Sample Time to expire. The values are: Minimum Frequency Sample Time (default), 2, 4, 8, 16, 32, 64, and 128.
Note that for the 1797-IJ2, if the Alternate Pulses to Terminate Sampling feature is selected, the values are: Minimum Frequency Sample Time (default), 13, 49, 51, 61, 81, 102, and 107.
Wire-Off/Missing Pulse Fault Select Mode
Lets you select the mode to use if a wire off or missing pulse detection is detected for any input (Frequency or Gate). The values are: Disabled, Alarm only, Alarm/Maximum Frequency, and Alarm/Minimum Frequency.
Detect Frequency Input Wire-Off
This option detects a wire off condition on the frequency input. The frequency input is that of the device that you are trying to monitor. The values are Checked, or Unchecked (default).
Detect Gate Input Wire-Off
This option detects a wire off condition on the gate input. The gate input is used with the frequency input in order to determine the direction of rotation of the device you are monitoring. The values are Checked, or Unchecked (default).
Use Alternate Pulses to Terminate Sampling (1797-IJ2 only)
Lets you direct the Pulses to Terminate Sampling feature to use an alternate set of values for the Pulses to Terminate Sampling count.
Important:
This feature, when selected, applies to both channels on the module. The default is Unchecked.
OK
Click this button to accept your edits on any tab and close the dialog.
Cancel
Click this button to delete your edits on any tab and close the dialog.
Apply
Click this button to make your edits effective on any tab and continue editing.
If:
  • you are online in Program, Remote Program or Remote Run mode and,
  • this controller is the owner controller and,
  • you have changed the module’s configuration in the software,
when you click the Apply or the OK button, the information is automatically sent to the controller. The controller tries to send the information to the module (if the module’s connection is not inhibited). If you don’t click Apply or OK, your changes are not sent to the controller.
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