Compare - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
15.0
Revision date
2022-11-18
Language
English

The Compare folder in the control block palette contains comparison blocks such as Greater Than or Not Equal. All compare blocks have three inputs (though the differential only has influence for floating point comparisons). The blocks compare input number 1 with input number 2 using the differential (input number 3). The type of comparison depends on the statistical type.

The Comparison block provides the following reliability values: Math Overflow, Math Underflow, and Math Error.

Table 1. Compare Blocks

Type

Description

Inputs

Outputs

Equal (Boolean)

Provides equal logic for Boolean inputs. If the inputs are identical, the Present Value is True. Otherwise, the Present Value is False.

Input 1 (Boolean) 1

Input 2 (Boolean)1

Differential (Float)

Present Value (Boolean)1

Equal (Enum)

Provides equal logic for Enumeration (Enum) inputs. If the inputs are identical, the Present Value is True. Otherwise, the Present Value is False.

Input 1 (Enum)1

Input 2 (Enum)1

Differential (Float)

Present Value (Boolean)1

Equal (Float)

Provides equal logic for Floating (Float) inputs. When the Differential is 0, the numbers must be the same for the Present Value to be True. If the absolute value of Input 1 minus Input 2 is greater than half of the Differential, then the Present Value is False. If the Present Value is already False, the sign of the difference between Input 1 and Input 2 must change or become zero, and the absolute value of the difference must be less than or equal to half of the Differential for the Present Value to change to True. 2

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Greater Than or Equal

Provides greater than or equal logic where Input 1 must be greater than or equal to Input 2 for the Present Value to change to True. If the Present Value is already True, Input 1 must be less than Input 2 minus the Differential for the Present Value to change to False.

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Greater Than

Provides greater than logic where Input 1 must be greater than Input 2 for the Present Value to change to True. If the Present Value is already True, Input 1 must be less than or equal to Input 2 minus the Differential for the Present Value to change to False.

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Less Than or Equal

Provides less than or equal logic where Input 1 must be less than or equal to Input 2 for the Present Value to change to True. If the Present Value is already True, Input 1 must be greater than Input 2 plus the Differential for the Present Value to change to False.

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Less Than

Provides less than logic where Input 1 must be less than Input 2 for the Present Value to change to True. If the Present Value is already True, Input 1 must be greater than or equal to Input 2 plus the Differential for the Present Value to change to False.

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Not Equal (Boolean)

Provides NOT equal logic for Boolean inputs. If the inputs are identical, the Present Value is False. Otherwise, the Present Value is True.

Input 1 (Boolean)1

Input 2 (Boolean)1

Differential (Float)

Present Value (Boolean)1

Not Equal (Enum)

Provides NOT equal logic for Enumeration (Enum) inputs. If the inputs are identical, the Present Value is False. Otherwise, the Present Value is True.

Input 1 (Enum)1

Input 2 (Enum)1

Differential (Float)

Present Value (Boolean)1

Not Equal (Float)

Provides NOT equal logic for Floating (Float) inputs. If the absolute value of Input 1 minus Input 2 is greater than half of the Differential, then the Present Value is True. If the Present Value is already True, the sign of the difference between Input 1 and Input 2 must change or become zero, and the absolute value of the difference must be less than or equal to half of the Differential for the Present Value to change to False. When the Differential is 0, any difference between Input 1 and Input 2 makes the Present Value True.2

Input 1 (Float)1

Input 2 (Float)1

Differential (Float)

Present Value (Boolean)1

Figure 1. Interlock Behavior
1 This input or output is exposed for connection by default.
2 This block behaves the same as the Interlock object in the Metasys NAE. See the following example where the differential equals 2.0. The green upper lines are True, the black lower lines are False, and the x-axis is the difference between Input 1 and Input 2 (x-axis = Input 1 - Input 2).