Visual Basic .NET - Dual Relay Bricklet

This is the description of the Visual Basic .NET API bindings for the Dual Relay Bricklet. General information and technical specifications for the Dual Relay Bricklet are summarized in its hardware description.

An installation guide for the Visual Basic .NET API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (ExampleSimple.vb)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Imports System
Imports System.Threading
Imports Tinkerforge

Module ExampleSimple
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Dual Relay Bricklet

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim dr As New BrickletDualRelay(UID, ipcon) ' Create device object

        ipcon.Connect(HOST, PORT) ' Connect to brickd
        ' Don't use device before ipcon is connected

        ' Turn relays alternating on/off 10 times with 1 second delay
        Dim i As Integer
        For i = 0 To 4
            Thread.Sleep(1000)
            dr.SetState(True, False)
            Thread.Sleep(1000)
            dr.SetState(False, True)
        Next i

        Console.WriteLine("Press key to exit")
        Console.ReadLine()
        ipcon.Disconnect()
    End Sub
End Module

API

Since Visual Basic .NET does not support multiple return values directly, we use the ByRef keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

Basic Functions

Class BrickletDualRelay(ByVal uid As String, ByVal ipcon As IPConnection)

Creates an object with the unique device ID uid:

Dim dualRelay As New BrickletDualRelay("YOUR_DEVICE_UID", ipcon)

This object can then be used after the IP Connection is connected (see examples above).

Sub BrickletDualRelay.SetState(ByVal relay1 As Boolean, ByVal relay2 As Boolean)

Sets the state of the relays, true means on and false means off. For example: (true, false) turns relay 1 on and relay 2 off.

If you just want to set one of the relays and don't know the current state of the other relay, you can get the state with GetState() or you can use SetSelectedState().

Running monoflop timers will be overwritten if this function is called.

The default value is (false, false).

Sub BrickletDualRelay.GetState(ByRef relay1 As Boolean, ByRef relay2 As Boolean)

Returns the state of the relays, true means on and false means off.

Advanced Functions

Sub BrickletDualRelay.SetMonoflop(ByVal relay As Byte, ByVal state As Boolean, ByVal time As Long)

The first parameter can be 1 or 2 (relay 1 or relay 2). The second parameter is the desired state of the relay (true means on and false means off). The third parameter indicates the time (in ms) that the relay should hold the state.

If this function is called with the parameters (1, true, 1500): Relay 1 will turn on and in 1.5s it will turn off again.

A monoflop can be used as a failsafe mechanism. For example: Lets assume you have a RS485 bus and a Dual Relay Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds. The relay will be on all the time. If now the RS485 connection is lost, the relay will turn off in at most two seconds.

Sub BrickletDualRelay.GetMonoflop(ByVal relay As Byte, ByRef state As Boolean, ByRef time As Long, ByRef timeRemaining As Long)

Returns (for the given relay) the current state and the time as set by SetMonoflop() as well as the remaining time until the state flips.

If the timer is not running currently, the remaining time will be returned as 0.

Sub BrickletDualRelay.SetSelectedState(ByVal relay As Byte, ByVal state As Boolean)

Sets the state of the selected relay (1 or 2), true means on and false means off.

The other relay remains untouched.

Function BrickletDualRelay.GetAPIVersion() As Byte()

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

Function BrickletDualRelay.GetResponseExpected(ByVal functionId As Byte) As Boolean

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by SetResponseExpected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See SetResponseExpected() for the list of function ID constants available for this function.

Sub BrickletDualRelay.SetResponseExpected(ByVal functionId As Byte, ByVal responseExpected As Boolean)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletDualRelay.FUNCTION_SET_STATE = 1
  • BrickletDualRelay.FUNCTION_SET_MONOFLOP = 3
  • BrickletDualRelay.FUNCTION_SET_SELECTED_STATE = 6
Sub BrickletDualRelay.SetResponseExpectedAll(ByVal responseExpected As Boolean)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Sub BrickletDualRelay.GetIdentity(ByRef uid As String, ByRef connectedUid As String, ByRef position As Char, ByRef hardwareVersion() As Byte, ByRef firmwareVersion() As Byte, ByRef deviceIdentifier As Integer)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

Sub MyCallback(ByVal sender As BrickletDualRelay, ByVal value As Short)
    Console.WriteLine("Value: {0}", value)
End Sub

AddHandler dualRelay.ExampleCallback, AddressOf MyCallback

The available callback property and their type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

Event BrickletDualRelay.MonoflopDoneCallback(ByVal sender As BrickletDualRelay, ByVal relay As Byte, ByVal state As Boolean)

This callback is triggered whenever a monoflop timer reaches 0. The parameter contain the relay (1 or 2) and the current state of the relay (the state after the monoflop).

Constants

Const BrickletDualRelay.DEVICE_IDENTIFIER

This constant is used to identify a Dual Relay Bricklet.

The GetIdentity() function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

Const BrickletDualRelay.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Dual Relay Bricklet.