pas-gpib -- Full measurement framework for GPIB, USB-TMC, TCP/IP, ...

pas-gpib is a full framework to perform measurements with professional instruments controlled via GPIB, USB-TMC, TCP/IP, RS-232, ...

The framework is written in Pascal using FreePascal. It has a Pascal header translations for Linux GPIB including an object-oriented wrapper. A USB Test and Measurement class implementation is included.

Although this is work in progress, several protocols and instrumets are fully supported.

Design Principle

This package is organized into two major parts

• instruments
• device communicators

For each instrument (e.g., multimeter, scope, spectrum analyzer, ...) a dedicated class is implemented, which derives from TRemoteInstrument. These use a device communicator instance, which is a class which implements the IDeviceCommunicator interface.

See doc/UML.dia for an UML class diagram.

The TRemoteInstrument class holds an instance of an IDeviceCommunicator class. Therefore, to create an instrument object (e.g., TLeCroyWaveJet, which is derived from TRemoteInstrument), you have to supply an instance of a class implementing IDeviceCommunicator, e.g., TTCPLeCroyCommunicator.

Device Communicators

Currently, there are five device communicator classes

• TUSBTMCCommunicator
• TUSBLeCroyCommunicator
• TRS232Communicator
• TTCPCommunicator
• TTCPLeCroyCommunicator
• TGPIBCommunicator

These are implemented in Pascal units in devcom/.

The TUSBTMCCommunicator provides communication to instruments with a USB Test and Measurement Class (USB-TMC) interface [USBTMC10]. It uses TUSBTMCUSB488, which implements the USB-TMC USB488 Subclass [USB488] to provide IEEE-488 (GPIB) communication via USB. TUSBTMCUSB488 is derived from TUSBTMCBase, which implements the base USB-TMC communication. These classes are implemented in units in usb/.

[USBTMC10]

Universal Serial Bus Test and Measurement Class Specification (USBTMC), Revision 1.0, April 14, 2003

[USB488]

Universal Serial Bus Test and Measurement Class, Subclass USB488 Specification (USBTMC-USB488), Revision 1.0, April 14, 2003

[Truevolt]

Keysight Truevolt Series Digital Multimeters Operating and Service Guide, Part Number: 34460-90901, Edition 5, (August 18, 2017)

[E36300Prg]

Keysight E36300 Series Programmable DC Power Supplies Programming Guide, Manual Part Number E36311-90008, Edition 5, May 2018

The TUSBLeCroyCommunicator provides communication with LeCroy scopes which do not adhere to the USB-TMC specification. These include the WaveAce and WaveJet devices. It uses a `` TUSBLeCroy``, which implements a driver for the proprietary protocol. This was reverse engineered with the Windows "virtual COM port" driver.

The TGPIBCommunicator provides communication to instruments with an IEEE-488 (GPIB) interface. It uses TGPIB, an object oriented wrapper for Linux GPIB. These are implemented in units in gpib/.

The class TTCPCommunicator provides basic TCP/IP communication to a host at a given TCP port. The descendant class TTCPLeCroyCommunicator adds a special header used by several LeCroy scopes when communicating via TCP/IP. Their protocol was reverse-engineered.

Instruments

Currently, rudimentary support for three devices is available

• TLeCroyWaveJet for LeCroy WaveJet scopes
• TKeithley2010 for Keithley 2010 multimeters
• TRohdeSchwarzFSEB for Rohde&Schwarz FSEB spectrum analyzers
• TAgilent34410A for Agilent 34410A and Keysight 34461A digital multimeters
• TKeysightE3631xA for Keysight E36300A programmable DC power supplies
• TKeithley2600 for Keithley 2602A SourceMeter SMU Instruments

Verified

• testusbtmc correctly lists (at least one) USB-TMC capable device and performs "*IDN?".
• testagilent34410a correctly communicates via USB-TMC as well as TCP with the device and performs a test measurement.
• testkeysighte3631xa correctly communicates via USB-TMC as well as TCP with the device and performs tests.
• testlecroywavejet3xx correctly communicates via TCP as well as USB with the device, performs settings and saves a screenshot.
• testkeithley2600 correctly communicates via TCP with the device and performs settings and measurements.

Directory Structure

Directory structure:

doc/
devcom/
instruments/
  agilent/
  keithley/
  lecroy/
  rohdeschwarz/
gpib/
usb/
pas-libusb/

References

The USB-TMC implementation uses libusb(x) 1.0 (see http://www.libusb.org/ and http://libusbx.sourceforge.net/ and the Pascal OOP wrapper at https://github.com/hansiglaser/pas-libusb/tree/libusb-1.0

This is referenced using Git Submodules. After cloning this project, you have to add the submodules too.

git clone https://github.com/hansiglaser/pas-gpib.git
cd pas-gpib
git submodule init
git submodule update

The submodule was added using the command (Important: https:// URL, not git:// URL, because github doesn't support "push" to git:// URLs!)

git submodule add -b libusb-1.0 https://github.com/hansiglaser/pas-libusb.git pas-libusb
git commit

To change a submodule within this main project and then commit and push to GitHub, a few things must be considered. A submodule by default is a 'Detached Head' this means it isn't on a branch.

cd pas-libusb/
git checkout libusb-1.0    # switch to a branch
# make changes
git add ...                # stage changes
git commit                 # commit
git push                   # and push to GitHub
cd ../..
git submodule              # shows that submodules are at a newer state
                           # than referenced by the main project
git add pas-libusb         # tell git to use the most current revision of
                           # this submodule
git commit                 # commit
git push                   # and push to GitHub

TODO

• FSEB: search manual, add functions and stuff to build test program
• document how to get Linux-GPIB in Debian (with direct SVN checkout or so)

• add lots of devices

  • Agilent E3631A Power Supply
  • Agilent 33220A Arbitrary Waveform Generator

• add many functions to devices, always specify reference manual

• add test programs

  • Rohde&Schwarz FSEB to get the nice image with satellite spectrum
  • Keithley 2010 with the switcher card to demonstrate the settling time (and add a comment on this example to TKeithley2010.SelectChannel)

• dedicated section in this README about the test programs

• TKeithely2010:

  • generalize to 2000
  • select DCV/ACV/DCI/ACI/Ohm2/Ohm4/Freq/Temp, many more functions

• TKeithley2600:

  • add methods PrintBuffer and PrintNumber, care for "Trim" in Query()!
  • add method SetDataFormat which sets "format.data = ..." and stores this information for later use by PrintBuffer and PrintNumber; but hide "format.byteorder" and always set it to what is easiest for the local machine; or include this with SetDataFormat
  • flexible buffer handling (MakeBuffer, ...)

• add communicator for LXI (LAN eXtensions for Instrumentation) http://en.wikipedia.org/wiki/LAN_eXtensions_for_Instrumentation mDNS/DNS-SD, SCPI Port (Telnet?)
• finish implementation of USB488, carefully read the spec
• License: use modified LGPL, the individual instrument drivers only have a few basic functions, actively encourage users of pas-gpib to contribute their added methods (which is required by the license, except they derive from the class) and their added instruments
• document: Standard Commands for Programmable Instruments (SCPI)
• see also TCL libraries http://wiki.tcl.tk/14780 and http://gpib-tcl.sourceforge.net/GPIB-Tcl.html