Answer:

From page 14 of the MiniSmart II Secure Smart Card Reader Command Interface (https://idtechproducts.atlassian.net/wiki/download/attachments/71697978/MiniSmart%20II%20Command%20Reference%2080161508-001.pdf?api=v2)

Get Internal Firmware Version Command Body is 78 31 – Get Internal Version Response Body is 06 + Version Number

You can find the dot NET SDK Demo tool on the Universal Library for Visual Studio - Home - Knowledge Base - Confluence (atlassian.net)