1. UNITRONICS
Alarm Task
Welcome and thank you for joining our learning object.
In the next few minutes we will talk about the Alarm task Terminology, Definition Of Alarms , Ladder Elements and get Alarm view on the PLC

2. Alarms Built in the controller Powerful function (V130/V350/V570)
Movie
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3. What is an alarm?
An Alarm is an event that must be reported to the machine operator
The event is a change in the Alarm’s Trigger condition, linked to Boolean or numeric value
An Alarm can:
Provide instructions
Require operator action
Play an active role in conditions
running the process
So what do we define as an alarm?
Alarm is an event, which requires user notification.
This event can be caused by a change in a Boolean element, like an input, output, timer or bit, or a numeric value pause like the temperature, pressure or any other value stored in a register,.
Setting an alarm can generate a notification for the user, or even take an active roll in the application, preventing the process to continue till it's cleared.
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4. Alarms HMI is already built in – no need of special design
Vision controllers support up to 128 Alarms,
divided into up to 16 groups
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5. Terminology- Active alarm
An alarm is active as long as its Trigger condition is met.
Whenever the Trigger Condition is:
True, the Alarm is active
False, the Alarm is inactive
An active alarm cannot be reset.
When active, an alarm is marked with the character ‘Y’ in the Alarm Details display
Active alarm – an alarm is considered active as long as the condition, defined as the trigger of it, is met. If we define an alarm when an input, coming from a photo cell is on, then as long as the photo cell is blocked, the alarm is active.
When the alarm is active it can not be reset.
When the alarm is no longer active, it turns into being pending for either view, acknowledge or reset.
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6. Groups definition on the PC
Pause Alarms
Clear pending alarms and rescan bit
Number of active alarms
Alarm is Active
pending for reset /view / acknowledge
Alarm is Pending
How to do it
Alarms may be divided into groups The different groups can represent different aspect of the machine or the process like geographical section, different components, level of importance etc.
Every group has a set of operands that represents what is the group's status…
There is one group that is default to the task and that is the "general collection group" and it's our intention that all alarm that has no common characteristic will be defined in it
Let's review the operands that are related to every group
*Pause alarm – this is the bit that one will turn on to suspend the alarms in the group or all the alarms if it’s the global operand.
*Clear pending alarms and rescan – this is the bit that one will set in order to reset the alarm in the group or all the alarms, if it’s the global operand. and restart the scan of the task
*Number of active alarms- a register that holds the amount of alarms which are now in Active status (the trigger of the alarm is on)
*Alarm is Active-a bit that indicates that there is an active alarm
*Number of Pending Alarms- a register that holds the amount of alarms which are pending for view, acknowledge or reset
*and Alarm is pending - a bit that indicate that there is a pending alarm.
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7. Alarms Alarms in groups Large option for trigger alarms
Option for help/comments with each alarm
Option to set password for acknowledge/reset the alarm
Multilingual support – via String Library
Alarm history
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8. Alarm Displays There are four types of displays
Groups with Pending Alarms
Alarms in Group
Alarm Details
Alarm History
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
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9. Alarm Displays Groups with Pending Alarms
Alarms are arranged in groups.
This display shows all groups that contain one or more pending Alarms. If the Alarms in a group are no longer pending,the group is not displayed.
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
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10. Alarm Displays Alarms in Group
Alarm ID number, assigned when the Alarm is created. ID
Time stamp of the most recent time the Alarm became Active.
Time On
If the Ack button has been pressed.
Ack
The Alarm name assigned in the Alarms Configuration.
Alarm Name
drills down to the details of the specific Alarm.
Details
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
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11. Alarm Displays Alarm Details The Alarm's Group ID and Name. Group
The Alarm's ID and name. ID
Date and time stamp of the most recent time the Alarm became Active.
Date
The number of times the Alarm became Active before Pending action is taken.
Count
Shows if the Alarm's Trigger condition is true.
Active
This window contains instructions for the machine operator.
Additional info
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
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12. Alarm Displays Alarm History
One can request that an alarm will be logged.
Up to 256 alarms can be saved in the memory of the PLC. when it is full it functions according to FIFO.
Alarms from the history buffer can be viewed in the alarms history display
One can request that an alarm will be logged. With the alarm the system will log different parameters like duration time started time ended and time for when the alarm was cleared (if reset or acknowledgment was requested)
Up to 256 alarms can be saved in the memory of the PLC More can be saved in a memory card . Alarms will be copied to the card automatically, by the operating system.
Alarms from the history buffer can be viewed in the alarms history display
Note: If the PLC contains an SD card, you can turn SB 352 ON
to enable the PLC to write the history to the SD card.
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13. Alarm Displays Alarm Pause
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
When the Pause icon appears at the bottom of the display, it means that the Alarms action is suspended.
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14. How does it run? The alarm task is running as part of the PLC's cycle
The task's displays are part of the operating system
It's up to the user to call the alarm's displays
Important!
When the alarm’s displays are on, the applications display is still active in the background and subroutines that are called under it are still running
The alarm task is running as part of the PLCs cycle and independently of the ladder checks the status of the triggers linked to the alarms.
The alarm task has its own displays. defined by the operating system .
Those displays are not editable although the user can change the strings that take part in it.
When one of the alarms becomes active and the relevant bit is on it's up to the user to change the HMI display so the alarms display will appear.
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15. Ladder Elements
One can jump to the group display, the alarms in group display or to a detailed alarm display.
The jump will be done only if the conditions are met
While in the alarm displays of the operating system. navigation is done by using the ESC and drill down button In order to get into the task's displays. the Visilogic is providing ladder elements that allows jumping to the group display. the alarms in group display or to a detailed alarm display.
Getting back to the application's HMI is either via the ESC button or by setting the alarms task system bit 351
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16. Thank You
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17. Terminology Active alarm Pending for view Pending for acknowledge
Pending for reset
Before learning about the alarm task, let's review some of the topic's terminology.
An alarm can be in one of 4 statuses
Active alarm, for when the condition of the alarm is triggered
Different type of Pending, where the alarm is waiting for a user's respond.
The next few slides we will review for different statuses
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18. Test your Knowledge: Active Alarm
Can an operator reset an alarm while the temperature is above a set point ?
We have defined an alarm triggered by the temperature exceeding a set point.
Can an operator reset an alarm while the temperature is above a set point ?
Submit
Clear
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19. Groups definition on the PC
Lets open
VisiLogic application
We call the alarm task from the navigation tree of the Visilogic
The alarm task can be build out of several groups, where the users groups are like folders, holding several alarms that has the same characteristic.
One group that is default to the task is the general collection group that contains all the alarms that has nothing in common.
When we call the alarm task we have to define the global operands of it, as explained before
We select the pause and clear bits, the number of active alarms and the alarm active bit, the amount of pending alarms and the alarm pending bit.
We will have to assign the same amount of operands for every group that we will create.
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