Legacy Document

Inside Macintosh: Networking With Open Transport / Part 2 - Open Transport Reference

Chapter 31 - Serial Endpoint Reference / Serial-Specific Commands

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I_SetSerialXOffState

This command sets the XOFF state of the serial port. Setting XOFF is equivalent to receiving an XOFF character, and clearing XOFF is equivalent to receiving an XON character. A value of kOTSerialForceXOffFalse unconditionally clears the XOFF state, while a value of kOTSerialForceXOffTrue unconditionally sets it. The following line of code unconditionally sets the XOFF state:

OTIoctl(theSerialEndpoint, I_SetSerialXOffState, kOTSerialForceXOffTrue);

Setting the XOFF state is equivalent to using a serial driver control call with a csCode value of 21, and clearing the XOFF state is equivalent to using a csCode value of 22.