We can successfully communicate with an instrument using the PCI-8433 interface card with the Microsoft VB.NET COM control. But we get a framing error if we try to read more than 44 bytes with MAX at 921600 baud. We get the same error using the Measurement Studio VISA interface in VB.NET (NationalInstruments.VisaNS.SerialSession).
At 115200 baud, MAX lets us read any length with that card. But at 921600 baud, MAX only lets us read up to 44 bytes (45 including the termination character). Note that the failed SCPI command requests 45 bytes but we read 46 to get the termination character.
We can read any amount with the VB.NET COM control. Both MAX and VB.NET COM are set to 921600 baud, 8 data bits, 2 stop bits and no parity. See the images below for the MAX error and settings.
VB.NET COM lets us reliably read any length at any rate up to 1843200 baud.
