In a Process Control rule that defines conditions for the values of tags, you need to specify the type of each condition. Each type has a certain number of additional settings that also include tags.
You can specify the types of conditions when performing the following actions:
Select the Process control tab in the Console window.
If the list of Process Control rules contains groups, select the group to which you need to move the new rule. You can select the group itself or one of the existing rules from the group.
Click the Add rule button.
The rule editor appears in the lower part of the tab.
The application Server will begin to register events based on the changes made to the rule.
In the drop-down list of condition types, you can select one of the following options:
Equal to – the value of the controlled tag is equal to the specified value.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int, bool, string type.
Parameter 2: specified value (constant or tag).
Does not equal – the value of the controlled tag is not equal to the specified value.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int, bool, string type.
Parameter 2: specified value (constant or tag).
Less than – the value of the controlled tag is less than the specified minimum permissible value.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int, float type.
Parameter 2: minimum permitted value (constant or tag).
Greater than – the value of the controlled tag is greater than the specified maximum permissible value.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int, float type.
Parameter 2: maximum permitted value (constant or tag).
Deviation exceeds allowance – if the controlled tag value differs from the specified value by more than the value of the allowance parameter.
Three parameters are used in this type of condition:
Parameter 1: controlled tag of the int, float type.
Parameter 2: specified value (constant or tag).
Parameter 3: allowance as a percentage of the specified value (constant – an unsigned number in the range from 0.001 to 100).
Out of range – the value of the controlled tag is outside of the specified range.
Three parameters are used in this type of condition:
Parameter 1: controlled tag of the int, float type.
Parameter 2: lower boundary of the range (constant or tag).
Parameter 3: upper boundary of the range (constant or tag).
Value has changed – the value of the controlled tag is changing.
One parameter is used in this type of condition: controlled tag of any type.
Tag bit equals – the value of the monitored bit in the controlled tag is equal to the specified value.
Three parameters are used in this type of condition:
Parameter 1: controlled tag of the int or unsigned int type.
Parameter 2: sequence number of the monitored bit in the tag (integer within the range corresponding to the data type of the selected tag: from 1 to 8, 16, 32 or 64).
Parameter 3: value of the monitored bit in the tag (specified as one of two integers: zero or one).
Detection – the controlled tag was detected in the traffic being monitored.
One parameter is used in this type of condition: controlled tag of any type.
Change exceeds allowance – the change in the value of the controlled tag exceeds the allowance relative to the previously registered value of the tag.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int, float type.
Parameter 2: allowance as a percentage of the previous value (constant – an unsigned number in the range from 0.001 to 100).
Tag bit has changed – the value of the monitored bit in the controlled tag is changed.
Two parameters are used in this type of condition:
Parameter 1: controlled tag of the int or unsigned int type.
Parameter 2: sequence number of the monitored bit in the tag (integer within the range corresponding to the data type of the selected tag: from 1 to 8, 16, 32 or 64).
To define a tag for a setting, you can select the relevant tag in the drop-down list or drag the tag from the Devices and tags list.
In the drop-down list to the right of the field containing the selected tag, you can select which most recent value of the tag is used in the rule. The following options are provided:
Read – the most recent tag value intercepted when reading the tag from the device.
Write – the most recent tag value intercepted when writing the tag to the device.
Read and write – the most recent tag value intercepted when reading or writing the tag.
You can define multiple conditions in a Process Control rule. To apply multiple conditions, you can select logical operators (AND / OR) and specify the priorities of conditions by using parentheses in logical expressions. You can add a condition by clicking the Add condition button. To remove an additional condition, use the button on the left of the condition.