NAME

USB::TMC - Perl interface to USB Test & Measurement (USBTMC) backend.

SYNOPSIS

use USB::TMC;

# Open usb connection to  Agilent 34410A digital multimeter
my $usbtmc = USB::TMC->new(
    vid => 0x0957,
    pid => 0x0607,
    serial => 'MY47000419', # only needed if vid/pid is ambiguous
);

$usbtmc->write(data => "*CLS\n");
$usbtmc->write(data => "VOLT:NPLC 10\n");

print $usbtmc->query(data => ":read?\n", length => 100);

my $capabilities = $usbtmc->get_capabilities();
my $support_term_char = $capabilities->{support_term_char};

DESCRIPTION

This module provides a user-space USBTMC driver.

Internally this module is based on USB::LibUSB.

Does not yet support the additional features of USBTMC-USB488. But those could easily be added if needed.

METHODS

Errors with USB transfers will result in a croak.

Use default timeout if timeout arg is not given.

new

my $usbtmc = USB::TMC->new(
    vid => $vid,
    pid => $pid,
    serial => $serial, # optional
    reset_device => 0, # default: do device reset
    debug_mode => 1,   # print lots of debug messages
    libusb_log_level => LIBUSB_LOG_LEVEL_DEBUG, # Import LIBUSB_LOG_LEVEL_* constant from USB::LibUSB
    term_char => "\n", # Stop a read request if the term_char occurs in the
                       # byte stream. Default: do not use term char
    timeout => 10,     # timeout in seconds. default: 5
);

write

$usbtmc->write(data => $data, timeout => $timeout);

Do DEV_DEP_MSG_OUT transfer.

read

my $data = $usbtmc->read(length => $read_length, timeout => $timeout);

Do REQUEST_DEV_DEP_MSG_IN and DEV_DEP_MSG_IN transfers.

Typically you will not need this method and only use "query".

query

my $data = $usbtmc->query(data => $data, length => $read_length, timeout => $timeout);

Send a query command and read the result.

get_capabilities

my $capabilites = $usbtmc->get_capabilities(timeout => $timeout);

Do GET_CAPABILITIES request.

The $capabilities hash contains the following keys:

bcdUSBTMC

listen_only

talk_only

accept_indicator_pulse

support_term_char