.\" Copyright (c) 1983, 1991 Regents of the University of California. .\" All rights reserved. .\" .\" %sccs.include.redist.man% .\" .\" @(#)ad.4 6.2 (Berkeley) 03/27/91 .\" .Dd .Dt AD 4 vax .Os BSD 4.2 .Sh NAME .Nm ad .Nd Data Translation A/D converter .Sh SYNOPSIS .Cd "device ad0 at uba0 csr 0170400 vector adintr" .Sh DESCRIPTION The .Nm \&ad driver provides an interface to the Data Translation A/D converter. This is .Em not a real-time driver, but merely allows the user process to sample the board's channels one at a time. Each minor device selects a different .Tn A/D board. .Pp The driver communicates to a user process by means of .Xr ioctl 2 Ns s. The .Dv AD_CHAN .Xr ioctl selects which channel of the board to read. For example, .Bd -literal -offset indent chan = 5; ioctl(fd, AD_CHAN, &chan); .Ed .Pp selects channel 5. The .Dv AD_READ .Xr ioctl 2 actually reads the data and returns it to the user process. An example is .Bd -literal -offset indent ioctl(fd, AD_READ, &data); .Ed .Sh FILES .Bl -tag -width /dev/adx -compact .It Pa /dev/ad .El .Sh DIAGNOSTICS None. .Sh HISTORY The .Nm driver appeared in .Bx 4.1 .