oCycleTimeH Object

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Description
Operation
Properties

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Description:

Measures the cycle time of a high-frequency input on a hardware specific I/O line.

The following table lists the size and availability of the oCycleTimeH Object.

	Object	Size	Description	A1	A2	B1	B2	C1
	oCycleTimeH	4 Bytes	Measures the cycle time of a high-frequency input using a hardware specific I/O line.					x

Operation:

When the Operate property is 1, the oCycleTimeH Object monitors I/O line 17 for a specified transition. When the input transitions, a counter value is copied to the Duration property and the counter is reset to 0.

The Mode property selects the transition that causes the copy which can be one of the following:

Every falling edge
Every rising edge
Every 4th rising edge
Every 16th rising edge

When the transition occurs, the 16-bit value of the counter is copied into the Value property. If another transition occurs before the Value property is read, the old value is overwritten by the new value. Note that any changes to the mode property only take affect when the operate property transitions from 0 to 1.

The DIO property is an instance of the oCCP object which is used to do the actual cycle time calculation. When the operate property transitions from 0 to 1, the oCCP object is configured so that it will use an oTimer object with an internal clock and a 1:1 prescale. Note that all instances of the oTimer object will use the PIC's Timer1 Hardware Module. Therefore, all instances of the oTimer object and objects that use the oTimer object will have the same 16-Bit count.

Properties:

The following table lists the properties of the oCCP Object:

Property
Description

Duration

A value that indicates the current duration of one cycle.

Object Class: oWord Value Range: 0 - 65535

Data Type: Numeric Default Value: 0

Mode

A value that selects how the cycle time is measured.

Object Class: oSelect0to3 Value Range: 0 - 3

Data Type: Numeric Default Value: 0

Any changes to this property will be ignored until the operate property transitions from 0 to 1.

PreScale Description

0 Every falling edge

1 Every rising edge

2 Every 4th rising edge

3 Every 16th rising edge

Operate

A value that selects whether or not the cycle time is measured.

Object Class: oOperate Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Operate Constant Description

0 cvOff The cycle time is not measured.

1 cvOn The cycle time is measured.

IOLine

I/O Line 17 used as the input line.

Object Class: oIOLine Value Range: 17

Data Type: Numeric (Read-Only) Default Value: 17

DIO

The PIC Hardware object used to measure the cycle time.

Object Class: oCCP Value Range: 0 - 65535

Data Type: Numeric Default Value: 0

Address

Returns a pointer to the address of the oCounter Object instance.

Object Class: oAddress Value Range: 0 - 127

Data Type: Pointer (Read Only) Default Value: Address of Object

Examples:

In the following example, the oCycleTimeH Object is used.

Visual Basic Syntax

C and Java Syntax

' This program measures the cycle
' time on I/O Line 17 and displays
' the result on I/O Group 1 and 3.

Dim C As New oCycleTimeH
Dim D As New oDIO16

Sub main()
  C.Mode = 1
  C.Operate = 1
  D.Direction = cvOutput
  Do
    D.State = C.Duration 
  Loop
End Sub

// This program measures the cycle
// time on I/O Line 17 and displays
// the result on I/O Group 1 and 3. 

oCycleTimeH C = New oCycleTimeH;
oDIO16 D = New oDIO16;

Void main(Void){
  C.Mode = 1;
  C.Operate = 1;
  D.Direction = cvOutput;
  Do{
    D.State = C.Duration;
  } While (1);
}

Basic Syntax

' This program measures the cycle
' time on I/O Line 17 and displays
' the result on I/O Group 1 and 3.

C Var oCycleTimeH(1,cvOn)
D Var oDIO16(cvOutput)

Do
  D.State = C.Duration 
Loop