Instrument Control Software

Depending on the particular application, software solutions for your organization may already be available in our software library or alternatively may be custom-developed based on a choice of either RS-232 or GP-IB interfaces.  For software language we currently recommend either Transera’s HT Basic for Windows or Microsoft’s Visual Basic. Each of these software languages has distinct strengths and the ultimate choice will depend on the particular application.

Interfaces:

The full capability of scientific instrumentation may be exploited by direct computer control.  Both Serial (e.g. RS-232) and Parallel (e.g. GP-IB) interfaces are available to connect and control programmable devices using a desktop PC.

RS-232: The Serial interface on the PC is normally accessible through the two rear-connected 9-pin RS-232 ports designated as COM1 and COM2.  Additional RS-232 ports may also be added to the PC and are typically designated as COM3 and COM4.  The RS232 protocol defines voltage levels and transmission format for sending data over the serial link.  The transmission operation is characterized by the serial baud rate, word size, start bits, stop bits and parity.  Many PC-compatible devices will set default conditions of 9600 baud rate, 1 stop bit and no parity. Some advantages of the RS-232 link include the relative easy of installation, the low cost and the availability of long connection lengths (up to 20 meters).  Serious disadvantages include the proliferation of non-standard protocols, and the early versions of software that often incorporate very poor RS-232 drivers.

GP-IB (IEEE-488): Hewlett Packard originally developed the parallel IEEE-488 interface bus, and designated it the HP-IB.  Due to its general applicability to instrument control and excellent control characteristics the bus soon gained widespread industry acceptance and the IEEE renamed it the GP-IB, for General Purpose Interface Bus.  The original IEEE-488.1 specification defines the bus protocols as well as the mechanical and electrical characteristics of the interface.  Each device connected to the bus is assigned a primary address although a secondary address may also be assigned.  In total the IEEE-488 standard allows up to 15 devices to be connected to a single interface board.  Advantages of the GP-IB include the excellent interface protocol standard and the multi device capability.  Drawbacks include the cost of the interface board (currently around $300-400) and the incompatibility between GP-IB boards from different manufacturers.  Overall, however, from an instrument control standpoint the GP-IB clearly represents the interface of choice.

Software:

Jerry Barker Consultants recommend one of two software languages – Transera’s HT Basic for Windows or Microsoft’s Visual Basic.

HT Basic for Windows.  This is Transera’s PC version of Hewlett Packard’s HP Basic for Workstations (also known as Rocky Mountain Basic, RMB).  HP Basic was originally developed in the late 1970’S specifically for I/O functionality and as such was highly recommended for instrument control applications.  At a later date, HP also introduced HP Basic Plus to allow HP Basic programs to incorporate a Windows-like interface.  Following the introduction of Basic Plus, HP then worked with Transera to produce a Windows version of HP Basic known (surprisingly) as HP Basic for Windows. Transera has heavily supported this product and later versions became known as HT Basic for Windows.  The main advantage of HT Basic over Microsoft Visual Basic is the relative ease of I/O and the excellent maths capabilities.  The downside is the lack of a compiled version.

See more information on HT Basic for Windows see the Transera website: www.htbasic.com.

MS Visual Basic.  This is Microsoft’s Basic programming language flagship.  It has supreme capability and functionality but is not always ideally suited to instrument control applications. Microsoft first introduced Visual Basic following the success of Windows 3.0.  This was their first attempt at a Windows oriented version of Basic with the language using QuickBasic type language syntax to build the Windows-based applications.  Visual Basic is now an industry standard programming language with outstanding versatility and support.  An additional advantage for Visual Basic over software languages such as HT Basic is the ability to produce a compiled version.  

Examples:

The kinds of software available from Jerry barker Consultants have been used previously to produce outstanding, high resolution data in a variety of industries. Below are a short list of examples:

Electrodeposition Software. Jerry Barker Consultants have the capability to develop novel deposition procedures which can be used in conjunction with our deposition hardware to create advanced electrodeposition systems. Example systems include those based on: Under Potential Deposition (UPD);  the measurement of the Quasi Rest Potential (QRP); and Pulsed Plating and Current Reversal regimens. These systems may be employed for the deposition of complex materials such as compound and elemental semiconductors, advanced electroactive materails, conductive polymers, battery materials etc.

In-situ Electrochemistry.  Standard electrochemical methods may be used in conjunction with analytical techniques to develop in-situ methods. Jerry Barker Consultants have considerable expertise in combining electrochemistry with, for example, un-visible spectroscopy, Raman spectroscopy, x-ray diffraction, as well as thickness and pressure transducers.

Electrochemical Voltage Spectroscopy, (EVS).  This method involves a voltage step protocol which provides a high resolution approximation of the (thermodynamic) open circuit voltage curve for the electrochemical system under test. Appropriate implemention of this technique allows direct determination of the differential capacity data for the system, which have been demonstrated to determine order-disorder and structural ordering phenomena in alkali insertion reactions. Kinetic parameters and phase nucleation effects may also be estimated by careful analysis of the current transient data.

Galvanostatic and Potentiostatic Intermittant Titration Techniques, (GITT and PITT). These are pulse-transient technques useful for determining the kinetic parameters in alkali metal insertion systems. A small constant current (or potential) step in applied to the system under test, while the transient voltage (or current) is recorded as a function of time. The change of voltage (or current) following the pulse determines the dependence of the cell voltage (or current) on the concentration of the electroactive species.

Electrochemical Impedance Spectroscopy, (EIS). Several systems are available for these ac impedance measurements. The careful implementation of this method allows one to reasonablky de-convolute the indivdual electrode contribution to the overall cellipedance. Moreover, ohmic, interfacial, kinetic and electrolye contributions may be determined.

Current Interrupt (CI). These dc impedance measurements are often carried out on battery and related electrochemiucal systems and may be considered complementary  to the ac (EIS) methods. The test conditions are carefully controlled to allow an estimation and de-convolution of the ohmic and non-ohmic (polarization) contributions to the overall system impedance.

Constant Current Cycling. This is the standard test method for electrochemical assessment of new battery electrode materials. The depedence of the electrode voltage versus charge at various charge/discharge rates may be used to determine material specific capacity as well as some (limited) kinetic information.