---
name: "pt"
section: "4freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "12.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/pt/4freebsd"
---

# pt(4freebsd)

SCSI processor type driver

## NAME

**pt** – SCSI processor type driver

## SYNOPSIS

**device** **pt**

## DESCRIPTION

The **pt** driver provides support for a SCSI processor type device. These are usually scanners and other devices using the SCSI link as a communication interface with device specific commands embedded in the data stream.

A SCSI adapter must be separately configured into the system before this driver can be used.

This device supports [read(2)](/read/2.md) and [write(2)](/write/2.md), and the [ioctl(2)](/ioctl/2.md) calls described below.

## IOCTLS

The following [ioctl(2)](/ioctl/2.md) calls are supported by the **pt** driver. They are defined in the header file ⟨sys/ptio.h⟩.

- PTIOCGETTIMEOUT

  This ioctl allows userland applications to fetch the current **pt** driver read and write timeout. The value returned is in seconds.

- PTIOCSETTIMEOUT

  This ioctl allows userland applications to set the current **pt** driver read and write timeouts. The value should be in seconds.

## FILES

- */dev/pt**N*

  the *N*th processor device.

## SEE ALSO

[cam(4)](/cam/4.md)

## HISTORY

The **pt** driver appeared in FreeBSD 2.1.