Am I right in assuming that HT BASIC has no direct connection with VISA? Therefore to communicate with some NI cards then I would need to create a LabView DLL in the ‘C’ format and call it from HT BASIC via its DLL interface?
The current version of HTBasic now includes a VISA driver: LOAD BIN “VISA;…” (or use Device Setup to configure). There is also an LXI driver that is VISA compliant. You can try out these device drivers by downloading the Trial version of HTBasic.
Here is a simple program that simply loads the VISA driver for the instrument at ASRL3::INSTR. It outputs *IDN to the instrument and then enters the response and stores it in a string variable. Finally it prints out the returned value in the string variable.
LOAD BIN "VISA;DEV ASRL3::INSTR ISC 7"
PRINT "The connected device is: ",S$
An alternative to loading the driver in code is to use the Device Setup under the tools menu.