Modem Control

R2026b

Control state of RTS and DTR output lines on serial port

• 

Modem Control block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Simulink Real-Time / RS232 / Mainboard

Description

The Modem Control block controls the state of either or both of the Request To Send (RTS) and Data Terminal Ready (DTR) output lines of the serial port on the Speedgoat^® target computer. To choose which output lines to control, select the RTS and DTR parameters.

Examples

ASCII Encoding/Decoding Loopback Test

Send ASCII data over a serial link.

• Open Script

ASCII Encoding/Decoding Resync Loopback Test

Use the ability of the FIFO Read HDRS block to resynchronize after being repeatedly disabled and apply this ability to resolve errors such as when a message is only partially complete at the time the read is attempted.

• Open Script

Binary Encoding/Decoding Loopback Test

Send Binary data over a serial link.

• Open Script

Binary Encoding/Decoding Resync Loopback Test

Use the ability of the FIFO Read BINARY block to handle messages that are interrupted and only partially complete.

• Open Script

Simple ASCII Encoding/Decoding Loopback Test (with Baseboard Blocks)

Convert a single floating point number to ASCII and transmit the value over a serial link.

• Open Script

ASCII Encoding/Decoding Loopback Test (with Baseboard Blocks)

Send ASCII data over a serial link.

• Open Script

ASCII Encoding/Decoding Resync Loopback Test (with Baseboard Blocks)

Use the ability of the FIFO Read HDRS block to resynchronize after being repeatedly disabled and apply this ability to resolve errors such as when a message is only partially complete at the time the read is attempted.

• Open Script

Binary Encoding/Decoding Loopback Test (with Baseboard Blocks)

Send Binary data over a serial link.

• Open Script

Binary Encoding/Decoding Resync Loopback Test (with Baseboard Blocks)

Use the ability of the FIFO Read BINARY block to handle messages that are interrupted and only partially complete.

• Open Script

Ports

Input

RTS — Level-sensitive signal for setting ready-to-send line

double

The behavior of the block is:

• RTS > 0.5 — The block asserts the RTS control bit to true. The output goes to a positive voltage.

• RTS ≤ 0.5 — The block asserts the RTS control bit to false. The output goes to a negative voltage.

Dependency

If the RTS parameter is off, this input has no effect.

DTR — Level-sensitive signal for setting data-terminal-ready line

double

The behavior of the block is:

• DTR > 0.5 — The block asserts the DTR control bit to true. The output goes to a positive voltage.

• DTR ≤ 0.5 — The block asserts the DTR control bit to false. The output goes to a negative voltage.

Dependency

If the DTR parameter is off, this input has no effect.

Parameters

RTS — Enable control of RTS line for serial device

on (default) | off

Select this check box to control the RTS line for this board.

Programmatic Use

Block Parameter: rts

DTR — Enable control of DTR line for serial device

on (default) | off

Select this check box to control the DTR line for this board.

Programmatic Use

Block Parameter: dtr

Serial port type — Port type that is being accessed

Legacy Serial Port (default) | USB Serial Port | Specify

Specify the serial port type for communications. Choose Legacy Serial Port or USB Serial Port to specify the type of port used. Or, choose Specify to manually specify the path of the port used. For more information about serial ports, see RS-232 Serial Communication.

Dependencies

Setting Serial port type to Legacy Serial Port or USB Serial Port displays the Serial port number parameter in which you can specify the port number.

Setting Serial port type to Specify displays the Serial port parameter in which you can specify the port path.

Programmatic Use

Block Parameter: portType

Serial port number — Port number that is being accessed

1 (default) | positive integer

Specify the serial port number for communications.

If using USB-to-serial adapters, the target computer detects these adapters as ttySUSB0, ttySUSB1, and so on in the order that the adapters are connected to the serial devices.

The order of port assignment is retained through the power cycle of the target computer or serial device if there is no change in the connections to the ports.

Dependencies

This parameter is visible if Serial port type is set to Legacy Serial Port or USB Serial Port.

Programmatic Use

Block Parameter: portNum

Serial port — Serial port device path that is being accessed

/dev/ttyS0 (default) | node path

Specify the serial port device path for communications. The path can be the device path of a Legacy Serial Port or USB Serial Port.

Dependencies

This parameter is visible if Serial port type is set to Specify.

Programmatic Use

Block Parameter: nodePath

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"slrealtimeseriallib/Mainboard/Modem Control"

Example: add_block("slrealtimeseriallib/Mainboard/Modem Control","myModel/myBlock",MakeNameUnique="on")

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2020b