#!/usr/local/bin/perl
##
## write_dac_current - set the value of an EAC DAC
##
## Usage: write_dac_current <eac> <dac> <current>
## Example write_dac_current eac1 2 .5
##
##
## FxxxxxZ = bad command data 
## bhimebau 9/13/04  - script creation

use Socket;

if (@ARGV != 3) {
  print "\nUSAGE: write_dac_current <eac_name> <dac> <dac_current_mA>\n";
  print "EXAMPLE: write_dac_current eac1 2 0.5\n";
  print "Command DAC 2 on eac1 to output  0.5mA\n\n";
  exit;
}
$eac=shift;
$channel=shift;
$current=shift;


if (($eac!="eac1")||($eac!="eac2")||($eac!="eac3")||($eac!="eac4")) {
  print "command syntax error - $eac not found - you must target eac1, eac2, eac3, or eac4\n";
  exit;
}

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

if (($current>1)||($current<0)) {
    print "command_syntax_error - current must be between 0.000 and 1.000 mA\n";
    exit;
}

$dac_counts = $current*1023;
$round_counts = sprintf("%d",$dac_counts);

# 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");

$dac_string=sprintf("D%02x%03xZ",$channel,$round_counts);
print S "$dac_string\n";
$result = <S>;
print "$result";
close (S);