oFeedBack2 Object

• Description
• Operation
• Properties

• Examples
• Connections
• Related
• Version History & Bug list

A Hardware Object that reads a 2 x 1 matrix feedback loop.

The oFeedBack2 Object alternately toggles two I/O lines used for sending signals. A third I/O line is monitored for feedback.  If feedback is detected, then a value indicating which line's feedback was detected is calculated. 

The 2 signal lines are individually and sequentially set high (5-Volts) while the feedback lines is used to detect any feedback from the signals.  Feedback is detected when the feedback lines detects the signal being sent out by the signal lines.  The oFeedBack2 Object handles all the required I/O logic.  The InvertOut property inverts the logic state of the outgoing signals and the InvertIn property inverts the logic state that is considered a detection.

When the Operate property is set to 1 the 2 x 1 feedback matrix is scanned.  If any outgoing signal is detected on the feedback line, the Result property is updated with a value and the "Any" property is set to 1.

The value of the Result property is calculated by ((signal1) + (signal2 * 2)).  The "Any" property will remain at 1 so long as at least 1 signal is detected.  Once all feedback is lost, the "Any" property is be cleared to 0.

The four oLogic properties; Ch1Only, Ch2Only and Both are also updated each time the feedback status is determined.  These three properties are exclusive and only one will be true at any time.

When the Operate property is set to 0 the feedback matrix scanning is suspended until the Operate property is set back to 1.

The following table lists the properties of the oFeedBack2 Object:

Property	Description
Result	A value that indicates the result of testing the feed back loops. Object Class:  oNib   Value Range:  -1 to 1 Data Type:  Numeric   Default Value:  0 Value Description 0 Nether channel's feedback was detected. 1 The feedback from only channel 1 was detected. 2 The feedback from only channel 2 was detected. 3 The feedback from channel 1 and 2 was detected.
Ch1	A value that indicates that the first feedback loop returned the data. Object Class:  oVar1   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
Ch1Only	A value that indicates that ONLY the first feedback loop returned the data. Object Class:  oLogic   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
Ch2	A value that indicates that the second feedback loop returned the data. Object Class:  oVar1   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
Ch2Only	A value that indicates that ONLY the second feedback loop returned the data. Object Class:  oLogic   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
Both	A value that indicates that both feedback loops returned the data. Object Class:  oLogic   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
Any	A value that indicates that any feedback loop returned the data. Object Class:  oLogic   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0
IOLine1	A value that specifies which I/O Line is connected to the first signal driver. Object Class:  oIOLine   Value Range:  0 - 31 Data Type:  Numeric   Default Value:  0 Some I/O Lines have special purposes.  Be sure to see oIOLine help file for details.
IOLine2	A value that specifies which I/O Line is connected to the second signal driver. Object Class:  oIOLine   Value Range:  0 - 31 Data Type:  Numeric   Default Value:  0 Some I/O Lines have special purposes.  Be sure to see oIOLine help file for details.
InvertOut	A value that selects if the outputs to drivers are to be inverted. Object Class:  oSelect0to1   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0 Normally, the output lines specified by the IOLine1 and IOLine2 properties are set to logical high (+5 volts) when the feedback signal output.  By setting the InvertOut property to 1, the outputs can be inverted so that a logical low (0 volts) is used to output the signal. InvertOut Constant Description 0 cvFalse The outputs lines are taken to +5 volts to send the signal. 1 cvTrue The outputs lines are taken to 0 volts to send the signal.
IOLineS	A value that specifies which I/O Line is connected to the return sensor. Object Class:  oIOLine   Value Range:  0 - 31 Data Type:  Numeric   Default Value:  0 Some I/O Lines have special purposes.  Be sure to see oIOLine help file for details.
InvertIn	A value that selects if the input from the sensor is inverted. Object Class:  oSelect0to1   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0 Normally, the oFeedBack2 Object is expecting that a feedback detection is when the IOLineS property is taken to a logical high state.  By setting the InvertIn property to 1, the expected input can be inverted so that a logical low state indicates a detection. InvertIn Constant Description 0 cvFalse A detection is indicated with a logical 1. 1 cvTrue A detection is indicated with a logical 0.
Operate	A value that selects whether or not the feed back loops are being tested. Object Class:  oOperate   Value Range:  0 - 1 Data Type:  Numeric   Default Value:  0 Operate Constant Description 0 cvOff The feedback feed back loops are not being tested. 1 cvOn The feedback feed back loops are being tested.
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

' This program monitors ' two lines for feedback ' and displays the results ' on I/O lines 24 and 25. Dim A As New oFeedBack2 Dim B As New oDIO4 Sub Main() A.IOLine1 = 28 A.IOLine2 = 30 A.IOLineS = 29 A.InvertIn = cvTrue A.Operate = 1 B.IOPack = 3 B.Direction = cvOutput Do B.Value = A.Value Loop End Sub

Bugs: No known bugs.