Hi JimHTeradyne,
Are you using a Real Time Embedded Controller? The 8370 is a MXI controller and would not be considered as the NI computer as you mentioned. Could you please verify the model number of our controller?
It seems like if the "force property refresh" is true, the API contacts the target and re-populates all the properties. If the target is not online, then the properties would not correctly refresh and unexpected behavior could occur. If you are using Real Time, can you verify that your target is online through this entire process?
MJ
Application Engineer
National Instruments