Ieee-488 Bus Communication Overview; Usbtmc Interface; Set Up The Usbtmc Port For Remote Control - Fluke Calibration 5560A Programmer's Manual

5560A/5550A/5540A
Remote Programmers Manual

IEEE-488 Bus Communication Overview

Communication between the controller and the Calibrator takes place with commands established by
IEEE-488.1 standards and commands specifically related to the Calibrator. The commands in Tables
20 through 27 are all the remote commands, both common and device-dependent.
Definitions of the different types of messages used on the IEEE-488 bus follow:
• Device-dependent commands are messages used to transfer information directly between the
Calibrator and the IEEE-488 controller. Some commands cause an action to take place in the
Calibrator. Others, called queries in the IEEE-488.2 standards, ask for information, and always
generate a response message from the Calibrator. While message format is governed by
IEEE-488.2 standards, message content can be unique to the Calibrator. For example, device-
dependent commands are used to set the output mode and amplitude, and to switch from
standby to operate.
• Common commands defined by IEEE-488.2 standards are used for functions common to most bus
devices. Examples include the command to reset a device (*RST) and the query for device
identification (*IDN?). Common commands and queries can be identified easily because they all
begin with an asterisk (*).
• Interface messages defined by IEEE-488.1 standards have their own control lines, and others are
sent over the data lines by first asserting the control line ATN (Attention). It is important to note that
interface messages unlike device-dependent and common commands, are not sent literally (for
example, when a device-dependent query is sent to the Calibrator, the controller automatically
sends the interface message MTA (My Talk Address).

USBTMC Interface

Set Up the USBTMC Port for Remote Control

To use the USBTMC port for remote control, first install the necessary VISA (Virtual Instrument
Software Architecture) drivers on the host computer. Download the drivers from National Instruments
(http://www.ni.com).
NI-VISA contains a USB Test and Measurement Class (USBTMC) driver that supports the necessary
protocol to communicate with USBTMC class instruments. Once installed, the driver allows the host
computer to automatically recognize and communicate with USBTMC devices.
The USBTMC driver only recognizes USBTMC and USBTMC-488 devices. The driver does not
recognize other USB devices such as mass-storage devices, cameras, and mobile phones.
In this section, USBTMC refers to devices that support the USBTMC or USBTMC-USB488 protocol.
When you use USBTMC, a separate USB cable is necessary for each instrument that is connected to
the host computer.
1. Connect the Type A end of the cable to the host computer.
2. Connect the Type B end of the cable to the Calibrator USB/Control Device port.
3. Turn on the Calibrator. When the host computer detects the Calibrator, it automatically installs the
necessary USBTMC drivers (this is a one-time operation).
4. Make sure that the Calibrator is detected: right-click on the Windows Start icon and select Device
Manager. Under that is USB Test and Measurement Devices and under that, is USB Test and
Measurement Device (IVI).
5. Close the Device Manager on the PC.
4