ThingSpeak Input

Read input fields from ThingSpeak channel

• 

Libraries:
Simulink Desktop Real-Time / Internet of Things

Description

The ThingSpeak Input block reads numeric data from ThingSpeak™ channels.

By default, this block uses the public ThingSpeak server, api.thingspeak.com. To configure the ThingSpeak channel, click Configure channel parameters.

To access the web page for Channel number, click View channel web page.

This block does not synchronize the ThingSpeak timestamp with the simulation time. For example, assume that the block is set to a sample time of 0.1 s and that the channel update period is 20 s. The sensor acquires new data at time T and transmits it to the ThingSpeak server, which gives the data a timestamp. If new data arrives before the 20 s update period has passed, the new data is lost. The block runs every 0.1 s and gets new data only every 20 s. The rest of the time, the block gets old data.

Examples

Packet Input/Output

Transfer data through UDP communication protocol using binary encoding.

• Open Script

CAN Input/Output

Transfer data through CAN bus.

• Open Script

CAN Input/Output with Vehicle Network Toolbox

Transfer data through CAN bus by using the CAN Pack and CAN Unpack blocks available in Vehicle Network Toolbox™ block library.

• Open Script

Ports

Output

Data — Data read from channel

numeric

Scalar numeric data read from the ThingSpeak channel.

Example: 3.14159

Dependency

The setting of the Output data type parameter determines the port data type.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Parameters

Channel number — ThingSpeak channel being accessed

0 (default) | numeric

This parameter is read-only.

To select a channel, click the Configure channel parameters button. In the Network Services ThingSpeak dialog box, set the Channel ID parameter.

Programmatic Use

Block Parameter: DrvAddress

Configure channel parameters — Select and configure channel to access

(button)

To configure the channel, click this button. A dialog box displays the channel parameter settings.

To accept your changes, click OK. To test your changes, click Test. To revert your settings to their previous values, click Revert. To exit the dialog box without changing the settings, click Cancel.

Programmatic Use

Block Parameter: DrvName

Block Parameter: DrvOptions

ThingSpeak server — Server for data transfer

api.thingspeak.com (default) | character vector

The default value is the standard address of the public ThingSpeak server.

Programmatic Use

Block Parameter: DrvName

Block Parameter: DrvOptions

Channel ID — Unique channel

12397 (default) | numeric

Select a unique channel among the available channels.

You cannot read and write over the same ThingSpeak channel in the same model.

Programmatic Use

Block Parameter: DrvOptions

Read API key — Access key for reading from channel

character vector

By default, this key is the API key for the channel on the public server, api.thingspeak.com.

Programmatic Use

Block Parameter: DrvOptions

Update period (secs) — Read update period, in seconds

20 (default) | numeric

Time between successive reads over the channel.

Programmatic Use

Block Parameter: DrvOptions

View channel web page — Access web page for channel

(button)

To access the web page for Channel number, click View channel web page.

Programmatic Use

Block Parameter: DrvOptions

Sample time — Sample time of block

0.1 (default) | double

Enter a value, in seconds, that represents how frequently you want the block to execute and interact with the I/O hardware. The block synchronizes your model with the real-time clock at this sample rate.

If you are using a fixed-step solver, enter the value that you entered as the Fixed step size configuration parameter or an integer multiple of that value.

Programmatic Use

Block Parameter: SampleTime

Maximum missed ticks — Number of timer ticks by which your model can trail the kernel

10 (default) | integer

In Connected IO mode, enter the number of timer ticks that your model can lag behind the real-time kernel. When the model lags behind by this number or fewer timer ticks, the software assumes that the lag is temporary. It allows the model to catch up, even if the model misses some ticks. When the model lags by more than this number, the software reports an error and simulation stops.

In Run in Kernel mode, the software ignores this value.

Programmatic Use

Block Parameter: MaxMissedTicks

Show “Missed Ticks” port — Send number of missed ticks to port Missed Ticks

'off' (default) | 'on'

In Connected IO mode, select this check box to send the number of missed ticks to output port Missed Ticks.

In Run in Kernel mode, the Missed Ticks port is zero.

Programmatic Use

Block Parameter: ShowMissedTicks

Yield CPU when waiting — Yield CPU while kernel waits for hardware

'off' (default) | 'on'

In Connected IO mode, select this check box to grant other programs more CPU time while the kernel waits for a response from the hardware.

In Run in Kernel mode, the software ignores this value.

Programmatic Use

Block Parameter: YieldWhenWaiting

Channel fields to read — Define which parts of channel to read

1 (default) | [1–8]

You can read 1–8 fields from each channel. Use this parameter to ignore implementation-specific information and receive only the fields that your application requires.

Programmatic Use

Block Parameter: ChannelFields

Output data type — Define data type of output port

double (default) | single | int8 | uint8 | int16 | uint16 | int32 | uint32 | <data type expression>

Define the data type of the output port.

To open the Data Type Assistant, click the >> button. To close the Data Type Assistant, click the << button.

Programmatic Use

Block Parameter: DataTypeStr

Mode — Method of defining type

Built in (default) | Expression

Use a built-in type, such as double or one defined by a data type expression.

Programmatic Use

Block Parameter: OptParam

Type — Data type selector

double (default) | single | int8 | uint8 | int16 | uint16 | int32 | uint32

Set of built-in types that are available for constructing data type expressions.

Programmatic Use

Block Parameter: DataTypeStr

Data type override — Policy on a signal type mismatch

inherit (default) | off

• inherit — Port inherits type of signal that it is connected to.

• off — Port sets signal data type to the type defined by this block.

Programmatic Use

Block Parameter: DataTypeStr

Version History

Introduced in R2017b

R2024b: Update to blocks with port names

In R2024b, when you enable optional ports, such as Show "Missed Ticks" port, these Simulink^® Desktop Real-Time™ block ports appear with labels.