Modem Control

Control state of RTS and DTR output lines on serial port

  • Library:
  • Simulink Real-Time / RS232 / Mainboard

Description

The Modem Control block controls the state of either or both of the RTS and DTR output lines on the serial port. To choose which output lines to control, select the RTS and DTR parameters.

Ports

Input

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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.

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

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

Programmatic Use

Block Parameter: rts

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

Programmatic Use

Block Parameter: dtr

From the list, select a port to access:

  • COM1 — 0x3F8

  • COM2 — 0x2F8

  • COM3 — 0x3E8

  • COM4 — 0x2E8

  • Custom — A port that is set to an address other than the addresses for COM1, COM2, COM3, or COM4.

The value Custom causes the Base address parameter to become visible.

Programmatic Use

Block Parameter: boardtype

Use this base address to specify a Custom serial port.

The value Custom causes the Base address parameter to become visible.

Programmatic Use

Block Parameter: addr

Introduced in R2008a