LinearGraph Function Block

This function converts the input In to the output Out based on the linear graph curve defined by X1, X2, Y1, and Y2 and based on the Operation.

Figure 1: Linear Graph - Wire Sheet

Figure 2: Linear Graph - Property Sheet

 

Figure 3: LinearGraph-Logic Diagram-Endpoint Limited

Figure 4: Limit-Logic Diagram-Endpoint Unlimited

Figure 5: Limit-Logic Diagram-Startpoint Zero

 


Inputs

Input Name

Description

Enable

If it is set to "true", it enables the function block.

In

This is numeric input value.

X1

(In & Par)

X Value from point 1.

X2

(In & Par)

X Value from point 2.

Y1

(In & Par)

Y Value from point 1.

Y2

(In & Par)

Y Value from point 2.

Table 1:Inputs for Linear Graph

Outputs

Output Name

Description

Out

Linear graph curve calculated as following:

Out (In) = Y1 + (((In-X1)*(Y2-Y1)) / (X2-X1))

Table 2:Outputs for Linear Graph

Parameters

Parameter Name

Description

X1 Par

(In & Par)

If X1 is "null", X1 Par is used as parameter.

X Value from point 1.

X2 Par

(In & Par)

If X2 is "null", X2 Par is used as parameter.

X Value from point 2.

Y1 Par

(In & Par)

If Y1 is "null", Y1 Par is used as parameter.

Y Value from point 1.

Y2 Par

(In & Par)

If Y2 is "null", Y2 Par is used as parameter.

Y Value from point 2.

Operation

There are three operations:

- Endpoint Limited

- Endpoint Unlimited

- Startpoint_Zero (In Spyder controller called as Vav_Flow_Balance)

Out Save

Master Sync Enabled: If you set it to "true" the last output will be set as output for one cycle after the controller restarts. The application can use it to return to the same state before the controller restart

Out: To enable or disable the Out feature.

Table 3:Parameters for Linear Graph

Examples

1.       Converting from PID Cooling Output 0 - 100% into 50 - 100% for Cooling 02 to open first Clg01. If Clg01 is on 100%, open Clg02.

Figure 6: Linear Graph Example Cooling 2 calculation

2.       Conventional wired wallmodule with relative setpoint.

Figure 7: Linear Graph Example relative Setpt from conventional WM

3.       Conventional wired wallmodule with absolute setpoint °C.

Figure 8: Linear Graph Example absolute Setpt from conventional WM in °C

4.       Conventional wired wallmodule with absolute setpoint °F.

Figure 9: Linear Graph Example absolute Setpt from conventional WM in °F

Refer to General Description for general information about IRMN4 Function Blocks.