I/O complement and signal conditioning
The VW3A68201 is an extended I/O card for the Altivar 68 drive family, giving you one differential analog input (0...10 V DC, 10-bit resolution, 30 kOhm impedance), one software-configurable analog output (0...20 mA DC, 9-bit + sign, 500 Ohm impedance, 2 ms sampling), and four reader inputs accepting 0...10 V. That analog output sampling time of 2 ms matters if you're closing a speed or torque loop through the drive's analog input — it's fast enough for most process lines but not for servo-like response. The card draws its logic supply internally from the drive backplane — 24 V DC (21...27 V) for the logic inputs, and a separate 10 V DC (9...11 V) rail for the reader inputs, drawing under 0.01 A with a 1...10 kOhm impedance for overload and short-circuit protection. That means you don't need an external 10 V supply for the reader inputs; the card generates it, but the current budget is tight — keep the reader load light.
Protection and wiring
Digital inputs have reverse-polarity protection; the analog output has short-circuit protection. The screw terminal block accepts up to 1.5 mm² or AWG 16 — standard for control wiring. The relay discrete output handles positive or negative logic, and the assignable logic output can source up to 0.2 A.