I have a USB-8451 setup for I2C communication with a 24C11 EEPROM in a test system. One out of every ~20 attempts at programming the EEPROM will fail with the error code -301706 "NI-845x: The device reference is invalid. Verify that the supplied device reference contains a valid device name." When I check MAX, the 8451 is indeed missing from the device list. This is happening on three identically configured systems. I have tried replacing the 8451 controller and re-installing the drivers to no avail. The EEPROM is not bad, I can take it to a different system and it will program fine. I would appriciate any ideas on what to look at next. Could an I2C bus fault cause the 8451 to de-enumrate in windows?
You are getting error -301706, exactly when? Using the I2C write read.vi? or when you close the reference? I just wanto confirm that you are using LabVIEW to program it.
There is only one loop that accesses the 8451 hardware. The wierd thing is that when this problem occurs it seems to crash the entire visa system as I will get errors trying to access serial port devices after the 8451 error occurs. Upgrading to the 2.1.1 version of the 845x drivers seems to have fixed the test system in the lab. We'll see if that solves it on all systems.
