Hey Robert, thanks for the reply.

I send a hex code:
Dim xmtBuf() As Byte = {&H96, &H1, &H50, &H51, &H74}
serialPort.Write(xmtBuf, 0, xmtBuf.Length)

Which translates out to 96 01 50 51 74

The device I'm writing to reads this function and will respond as a hex as well, which I'm trying to read here:
Dim rcvBuf(1024) As Byte
serialPort.Read(rcvBuf, 0, rcvBuf.Length)

Thanks,
Ben.