---
title: "Subroutines and Functions"
slug: "subroutines-and-functions"
updated: 2024-01-30T14:29:34Z
published: 2024-01-30T14:29:34Z
canonical: "kb.dataparc.com/subroutines-and-functions"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.dataparc.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Subroutines and Functions

### Basic Subroutine with Error Handling

In general, subroutines in PARCcalc Config will begin with the following:

Option Explicit

Sub *SubRoutineName*()

On Error GoTo errhandler

The subroutine should then end with the following:

Exit Sub

errhandler:

errorcallback(Err,Error)

Resume Next

End Sub

Any other code will typically be placed in between these two sections.

### Sub.....End Sub.......Call

Sometimes it is helpful to put code into its own module. Here is an example of a subroutine called SaveSquarerootOfSum that takes the input and output tag names as arguments:

Sub SaveSquarerootOfSum(TagIn1 as Integer, TagIn2 as Integer, TagOut as Integer)

Tag(TagOut, sqr(GD(TagIn1) + GD(TagIn2)))

End Sub

In this case, “Call” (with parameters) executes the subroutine. The following is an example:

‘calculate the square root of the sum of Input tags 2 and 5. Put the result in Output tag 4

Call SaveSquarerootOfSum(2, 5, 4)

‘calculate the square root of the sum of Input tags 19 and 21. Put the result in Output tag 6

Call SaveSquarerootOfSum(19, 21, 6)

### Function.....End Function

Sometimes it is helpful to put code its own module. Following is an example. The function name (SaveSquarerootOfSum) is a variable that contains the value that is returned.

Name the Function “SquarerootOfSum” and define the input tags. The Function must be given a type at the end of the declaration (“Single”). The Function name must be assigned a value inside the routine.

Function SquarerootOfSum(TagIn1 as Integer, TagIn2 as Integer, TagOut as Integer) as Single

SquarerootOfSum = sqr(GD(TagIn1) + GD(TagIn2))

End Function

This function can then be called in other portions of the code. The following is an example:

‘calculate the square root of the sum of Input tags 2 and 5. Put the result in Output tag 4

Tag(4, SaveSquarerootOfSum(2, 5))

‘calculate the square root of the sum of Input tags 19 and 21. Put the result in Output tag 6

Tag(6, SaveSquarerootOfSum(19, 21))