A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at www.rbdinstruments.com
UPDATE: A new Actuel Beta featuring a data cursor and auto-save is now available.
Actuel, RBD’s Windows application for controlling the 9103 USB Picoammeter, has currently been updated with some great new features. While the official release is a few weeks away, the beta release contains some new features in addition to the previously previewed micro-window display.
Auto-Save while recording:
In response to customer requests, we’ve added a feature to automatically save data while recording. The auto-save feature comes in handy when leaving the 9103 unattended for long periods. While rare, brownouts, etc., can cause a temporary communication failure between the 9103 and PC, and USB failures can sometimes lock-up or crash a system. Auto-save ensures that data is stored to a text file every 5 minutes, and again when recording is stopped (for completeness).
Auto-save always works automatically when multiple 9103 picoammeters are synced together. Simply select the option for all instances of Actuel, then select the file name (and keep the Data window open for each instance you want to record/save from). The data from each 9103 will be appended to the file sequentially, separated by the device identifier.
Sometimes it’s handy to see the exact data at a particular point in time during or after data acquisition. While high sampling rates make it difficult to mouse-over every data point in large data sets, the data cursor can help track current vs. time more easily without the need to export data as text. By simply hovering over the graph, a vertical line appears, while current and time is displayed in the upper right-hand corner of the graph window.
As always, Actuel is free for all owners of a 9103 Picoammeter. Meanwhile, you can download the most recent version of Actuel here:
RBD’s 9103 USB PIcoammeter is packaged with Windows application software for control, current display, data-logging, and graphing. However, it’s often desirable to use the 9103 with other operating systems, integrate it with other hardware or software systems, and/or extend the capabilities of the application software. Fortunately, the 9103 utilizes an ASCII command set that exposes all of its features. Programming the 9103 Picoammeter is straightforward and easy to test.
A complete guide to programming the 9103 picoammeter can be viewed and downloaded from RBD’s website here. This post will give you an overview of setting up communications with the 9103 and the message structure for controlling the unit and gathering status and data.
Of course, every programming environment is different. As long as you are working with a tool that supports USB communication and text streaming, you can create a custom application for your 9103.
Setting up Communications
If you are using your 9103 with Windows, the installed driver creates a virtual serial COM port. RBD’s Actuel application software uses this port for communicating with the 9103, and any application you use to interface with the 9103 will use this same port for communications.
For other operating systems, you’ll need to download the appropriate driver from the manufacturer of the USB communications components, FTDI. Those drivers can be found here.
If you are interfacing the 9103 with LabView, drivers and scripts can be found on the 9103 downloads page.
The communications protocol for the 9103 is typical for many serial devices. Whether you configure the USB port using your operating system or program it within your application, the protocol is as follows:
Bits per Second (Baud Rate)
Sending and Receiving Commands
Communication with the 9103 is asynchronous. Most commands sent from the computer control device to the Picoammeter will be answered with a response, which may include an error message if there is a problem understanding/executing the command.
All messages are delivered as ASCII text – there is no binary message data. This includes the actual data delivered by the 9103, which is a formatted ASCII value.
Depending on your programming environment and application, you’ll normally be coding (at the least) logic to deliver the messages to the 9103, as well as to monitor the USB port and parse incoming messages.
Message Formats and Sample Messages
All messages are preceded by the “&” character, followed by a single character denoting the command or data type, as well as additional characters representing command parameters or data.
Here are a few examples:
I – From PC, command message to set the data sample interval, parameter is in milliseconds, 0015 to 9999.Example: ‘&I0500‘ sets the sampling interval to 500 milliseconds
F – From PC, controls the filter settings for the sample data. Allowed values are 000, 002, 004, 008, 016, 032, and 064.Example: ‘&F016‘ sets the filter value to 16
Data and status are passed back to the PC from the 9103 using a similar format. For example:
E – From device, sent if there was an error. Includes string description of error.
A full description of the command and data messages, as well as additional information on programming the 9103 Picoammeter are found in the 9103 User Guide.
Using Actuel’s Console Window For Debugging
If you are communicating with the 9103 using Windows, you can view the communications taking place in real-time using the Console window – simply click the Console button on the main window. You can also type commands here and see the results in real-time.
Two exciting new features are now available for the 9103 Picoammeter: Synchronization and Device Identification. These features transform the 9103 from a single current measurement device to a multi-channel picoammeter. Up to 127 channels!
Synchronization is provided by RBD’s free Actuel picoammeter control and display software. Multiple instances of the software now communicate start and stop information for sampling and recording of data. Additional features are also being added to facilitate exporting and combining of data-sets from multiple picoammeters. While the synchronization is not time sample-accurate, this small offset will not be an issue for most applications.
The newest version of RBD’s Actuel software (1.3) is now available. This update includes additional features such as the ability to run in either Windows Admin or User mode.
9103 firmware now includes the ability to set a unique string identifier for your 9103 Picoammeter. The ID can be easily changed at any time by the user, and is recalled when the 9103 is powered off/on. This makes it easier to identify 9103 Picoammeters in a multiple-unit environment.
All new 9103’s will include this feature; existing units can be upgraded for a nominal fee and shipping charge.
More information on the 9103 Picoammeter can be found on our website.