Some ITECH test equipment has a DSUB connector with a standard-breaking 5V TTL connector on it. This is a non-isolatd USB converter for this equipment, for interfacing to a PC.
It is known to work with at least the following models:
It should also work with all models in the IT6800 family, as well as several BK precision devices which they appear to be direct copies of.
Note that the A- and -+ versions of these test equipment generally have built-in USB ports that support USBTMC, which is somewhat easier to work with.
You can order the PCBs direct from the OSH park project, or use the gerbers and order from anywhere. You'll need the parts listed in the BOM, substituting a USB 'A' cable for the 4-pin header. The PCB is designed to be sodlered directly to a NorComp 171-009-103L001 DSUB connector, and the whole thing will fit in a NorComp 977-009-020R121 shroud.
See the python library readme for a tutorial on using the adapter with Python.