Stream Output - Transmit formatted ASCII data

Library

Real-Time Windows Target

Description

The Stream Output block sends formatted ASCII data. After you have added a Stream Output block to your model, double-click the Stream Output block to open the Block Parameters: Stream Output dialog box.

The driver must be Standard Devices > Serial Port, Standard Devices > File, or Standard Devices > UDP Protocol. Specify parameter values as required, then click OK or Apply. When you install a UDP device, enter port addresses in decimal format in the Standard Devices UDP Protocol dialog box.

Any serial output port can send data with sample rates up to 500 Hz. To enable a faster sample rate of up to 10 kHz for some output serial ports, see the following. The software does not support this option with all types of serial output hardware.

1. Click Install new board.

2. From the drop-down list, select Standard Devices > Serial Port.

   The Standard Devices Serial Port dialog box is displayed.

3. In the Standard Devices Serial Port dialog box, select the Direct port access check box.

4. Continue as usual, click OK when done.

Parameters

Sample time

Enter a value representing how frequently you want the block to execute and interact with the I/O hardware. The block will also synchronize your model with the real-time clock at this sample rate.

Tip   If you are using a fixed-step solver, you must enter the value you entered in the Fixed step size box from the Configuration Parameters dialog box, or an integer multiple of that value.

Maximum missed ticks

Enter the number of timer ticks that your model can lag behind the real-time kernel. When the model lags by more than this number, the block reports an error and simulation stops. Otherwise, simulation continues even if some ticks are missed.

Show "Missed Ticks" port

Select this check box to display the current number of missed ticks as a block output.

Yield CPU when waiting

Select this check box to grant other programs more CPU time while the kernel waits for a response from the hardware.

Input port sizes

Enter a port width, or vector of port widths. The number of elements determines the number of input ports. Each port has the width specified by the corresponding element. For example, specifying 3,1,2 indicates that the block has three input ports. The first is a vector of width 3, the second is a scalar, and the third is a vector of width 2, for a total of six elements. Only the widths need to be specified; any Simulink data type can be input.

Format string

Enter a specification in the same format used by C library I/O routines like printf. The format string describes the data to be sent. The format string must have the same number of specifiers as the sum of the elements of Input port sizes.

For example, assume that Input port sizes is 3,1,2. Then a Format string of '%d %d %d %f %d %d' would output ASCII representing: three integers from the vector on the first input port; a double from the scalar on the input second port; and two integers from the vector on the third input port.

If the data type specified in the Format string for a value differs from the type of the actual value, type conversion occurs automatically, and converted data that conforms to the Format string is output as ASCII to the device.

Show "Data Ready" port

Select this check box to indicate that the block has an output port that signals 1 if the block is ready to accept new data, and 0 otherwise.

Show "Data Error" port

Select this check box to indicate that the block has an output port that signals 1 if a data error has occurred, and 0 otherwise.

Initial string

Optional. Enter a string that is sent when simulation begins, before any other data that is output during simulation. The string can contain anything; it could be used to initialize a device. It is sent literally as specified, without translation using the Format string.

Final string

Optional. Enter a string that is sent when simulation ends, after any other data that is output during simulation. The string can contain anything; it could be used to shut down a device. It is sent literally as specified, without translation using the Format string

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