S-USB-2COM S-USB-2COM Dual USB - to - Serial adapter $47.95 | GAD668**S GAD668**S (GAD668--S) Analog Input Module, 8 channels, 0-5 V, 0-20 mA, +/-10 V, $1,320.00 | GDA672**S GDA672**S (GDA672--S) Analog Output Module, 2 channels, +/-10V output, 12-bit $970.00 |