Introduction
MET/CAL version 11 represents a significant change in the way MET/CAL communicates with instruments during a procedure. Since version 10.5, we have been making changes to allow us to add support for reference devices that use VISA interfaces like USBTMC and VXI-11/LAN. Prior to version 11, references, whether they were System Instruments with an FSC or User-Configured Instruments, could only be communicated with via RS-232 or GPIB interfaces. In version 11.0, we added support for USBTMC for User-Configured Instruments, and support for VXI-11/LAN for User-Configured Instruments will be added in version 11.1. Currently, all System Instruments will still only use RS-232 or GPIB, depending on which interfaces are available on the instrument, but if there is a specific FSC you want to use via USBTMC or VXI-11/LAN connections, please let us know so we can prioritize the required updates to that FSC.
In order to support this additional functionality, the team completely re-worked many of the underlying instrument communication structures, some of which were from the original versions of MET/CAL in 1989! Understandably, this means there is a somewhat different experience now when configuring instruments or running procedures, but these changes also make it easier to perform these tasks. Here are some of the specific changes that were made.
Instrument Configuration
The number of GPIB Boards is no longer configured in MET/CAL. Instead of needing to select None, 1, or 2, MET/CAL will automatically determine the number of boards/adapters attached to the system and present instruments from all available boards in the various dropdowns.
Previously, there were limited settings that could be configured in MET/CAL directly for communication, generally just the type of communication and a port or address. Now, after selecting the type of interface, additional settings are available using the "..." button to right of the drop down (1). Below are examples of configuring a User-Configured Instrument with IEEE-488 (GPIB) or USBTMC (USB). System instruments will have less interface settings, since many of the options are determiend by the code of the Instrument FSC.
Running a Procedure
Changes to instrument communication also extend to the device under test (DUT). As mentioned above, the number of GPIB boards is no longer specifically configured. However, existing behavior that automatically selected the DUT when it was the only instrument on GPIB1, while all configured standards were on GPIB0, continues to work. Additionally, if there is only one instrument found on the selected DUT interface (by using an instrument communication FSC like IEEE or SCPI), it is automatically selected as the DUT, and MET/CAL no longer prompts the user to enter the address. As a result, you generally will not see these familiar prompts in version 11.x:
In cases where there are multiple instruments found on the bus that are not at addresses of configured instruments, MET/CAL presents a dropdown of the items found, rather than requiring a text entry. There is a similar prompt for selecting VISA Resources.