Tag Properties: Alarms
Use the Tag Properties dialog to view the configured alarms for a selected tag. IWS disables this command if there are open alarm worksheets. Before using these dialogs, you should have already created the alarm groups.
ALARM TYPES:
- HiHi: A Very High alarm is present.
- Hi: A High alarm is present.
- Lo: A Low alarm is present.
- LoLo: A Very Low alarm is present.
- Rate: An alarm based on rate of change is present.
- Deviation: An alarm based on deviation from a given set point is present. Example:
- If SetPoint = 50, Deviation + = 5, Deviation − = 5, and Deviation Dead Band = 0.5;
- IWS generates an alarm when the temp ≥ 55 or temp ≤ 45; and
- A return to the normal occurs when temp ≤ 54.5 or temp ≥ 45.5.
ALARM LIMITS:
- HiHiLimit: When creating Very High alarms in the Tag Properties dialog, use this field to specify the limits. You can access this field during runtime and use it during modifications on the fly.
- HiLimit: When creating High alarms in the Tag Properties dialog, use this field to specify the limits. You can access this field during runtime and use it during modifications on the fly.
- LoLimit: When creating Low alarms in the Tag Properties dialog, use this field to specify the limits. You can access this field during runtime and use it during modifications on the fly.
- LoLoLimit: When creating Very Low alarms in the Tag Properties dialog, use this field to specify the limits. You can access this field during runtime and use it during modifications on the fly.
- DevSetpoint: Reference point for a tag value deviation that triggers an alarm. Define the alarm message in the Tag Properties dialog or on an Alarm worksheet. You can access this field during runtime.
- Dev+Limit: Limit deviation to a value higher than the DevSetpoint in a tag value that triggers an alarm. Define the alarm message in the Tag Properties dialog or on an Alarm worksheet. You can access this field during runtime.
- Dev+Limit: Limit deviation to a value lower than the DevSetpoint in a tag value that triggers an alarm. Define the alarm message in the Tag Properties dialog or on an Alarm worksheet. You can access this field during runtime.
- RateLimit: Limit of rate variation in a tag value that triggers an alarm. Define the alarm message in the Tag Properties dialog or on an Alarm worksheet. You can access this field during runtime.
Alarms for Integer and Real Type Tags
From the Tag Properties dialog, specify an alarm for integer and real-type tags as follows:
- Alarms Enabled checkbox: Click (check) to enable checking according to configuration.
- Remote Ack tag field: Type a tag to acknowledge this alarm.
- Dead Band Value field: Type a value of the filter for alarms normalization. For example: if the TEMP1 tag is configured with an alarm with Hi Limit = 90 and Dead Band = 5, then IWS generates an alarm when TEMP1 ≥ 90. The return to normal occurs when TEMP1 ≤ 85.
- Translation Enabled checkbox: Click (check) to enable the translation of messages defined on the Options tab in the Project Settings dialog. For additional information about translations, see Translation Tools.
Note: IWS saves Alarm messages with the Translation Enabled attribute enabled in a file called Alarm.TXT located in your project’s DATABASE directory.
- HiHi (HiHiLimit) checkbox: Click (check) to indicate a Very High alarm is present. Accessible during runtime.
- Hi (HiLimit) checkbox: Click (check) to indicate a High alarm is present. Accessible during runtime.
- Lo (LoLimit) checkbox: Click (check) to indicate a Low alarm is present. Accessible during runtime.
- LoLo (LoLoLimit) checkbox: Click (check) to indicate a Very Low alarm is present. Accessible during runtime.
- Rate (RateLimit) checkbox: Click (check) to indicate a Rate alarm is present. Accessible during runtime.
- Deviation+ checkbox: Click (check) to indicate a Deviation alarm is present. Accessible during runtime.
- Deviation- checkbox: Click (check) to indicate a Deviation alarm is present. Accessible during runtime.
- Deviation SetPoint field: Specify a reference point for the deviation. Accessible during runtime.
- Deviation Dead Band field: Specify a reference value for the deviation.
Alarms for Boolean-Type Tags
Use the Alarms-Bool Type tab on the Tag Properties dialog to specify alarm properties for Boolean-type tags.
Figure 1. Alarms-Bool Type Tab
Configure the parameters as follows:
- Alarms Enabled checkbox: Click (check) to enable checking according to configuration.
- Remote Ack tag field: Type a tag to enable remote alarm acknowlegement, which occurs when the tag values change.
- Translation Enabled checkbox: Click (check) to enable the translation of messages defined on the Options tab in the Project Settings dialog. For additional information about translations, see Translation Tools.
Note: IWS saves Alarm messages with the Translation Enabled attribute enabled in a file called Alarm.TXT located in your project’s DATABASE directory.
- Off checkbox: Click (enable) to generate an alarm message always when the tag value is zero.
- On checkbox: Click (enable) to generate an alarm message always when the tag value is one.
- Changed checkbox: Click (enable) to generate an alarm message always when the tag value changes.
- Text value pane: Use the Off, On, and Ack fields to configure mnemonics (for example, Closed or Open) for the Off, On, and Ack alarm states (Boolean tags only). During runtime, the Alarm Control object will display this text in the Value column of the alarm message. You can also access this text using the tag fields.
Note: If you do not configure a mnemonic, the Alarm Control object displays the tag value (0 or 1) in the Value column.