#!/usr/local/bin/perl
##
## triangle_source - uses a DAC channel to sweep the current from 0-1mA. The 
## target eac, channel, and number of steps in the sweep can be specified on 
## the command line.
##
## Usage: triange_source <eac> <dac> <steps_per_cycle>>
## Example triangle_source eac1 0 200
## sends out a triangle wave on channel 0 of eac1, outputs triangle wave in 200 steps
## per cycle.
##
## bhimebau 9/14/04  - script creation

use Socket;

if (@ARGV != 3) {
  print "\nUSAGE: triangle_source <eac_name> <dac> <steps_per_cycle> \n";
  print "EXAMPLE: triangle_source eac1 2 20\n";
  print "Repeatedly outputs triangle wave on DAC 2 of eac1 at 20 steps/cycle\n\n";
  exit;
}
$eac=shift;
$channel=shift;
$steps_per_cycle=shift;

if (($channel>15)||($channel<0)) {
    print "error - channel number must be between 0 and 15\n";
    exit;
}

if (($steps_per_cycle>512)||($steps_per_cycle<0)) {
    print "error - data must be between 0 and 512\n";
    exit;
}

$step_size = 1023/($steps_per_cycle*2);

# Socket setup
$iaddr = inet_aton("$eac") || die "no host: $eac";
$paddr = sockaddr_in("17000",$iaddr);
$proto = getprotobyname("tcp");
socket(S,PF_INET,SOCK_STREAM,$proto) || die "socket: $!";
connect(S, $paddr)                   || die "connect: $!";
select(S); $|=1; select("stdout");

$cdir=0;
while (1) {
    if ($dac_dat>=1023) {
	$cdir=1;
	$dac_dat=1023;
    }
    if ($dac_dat<=0) {
	$cdir=0;
	$dac_dat=0;
	close(S);
	sleep(2);
	socket(S,PF_INET,SOCK_STREAM,$proto) || die "socket: $!";
	connect(S, $paddr)                   || die "connect: $!";
	select(S); $|=1; select("stdout");
    }
    $dac_string=sprintf("D%02x%03xZ",$channel,$dac_dat);
    print S "$dac_string\n";
    $result = <S>;

    if ($cdir==0) {
	$dac_dat=$dac_dat+$step_size;
    }
    else {
	$dac_dat=$dac_dat-$step_size;
    }
}
close (S);