The VW3A3E406 is an encoder interface card from the Schneider Electric Altivar range, designed to connect incremental encoders to a variable-speed drive. It accepts A, B, complement of A, complement of B, and AB/A input signals — the standard quadrature format plus a marker channel — and outputs a push-pull signal at up to 300 kHz. The 1 kOhm input impedance presents a defined load to the encoder, which matters when the cable run approaches the 500 m maximum distance.
The 300 kHz maximum operating frequency sets the upper bound on encoder pulse rate — above that, the card loses counts. For a 5000 PPR encoder, that caps shaft speed at 3600 RPM (300,000 / 5000 × 60). The 15 V DC supply (limits 15...16 V) is specific; do not assume a 24 V encoder supply will work without a step-down. Overload and short-circuit protection on the output side means the card can survive a wiring fault on the push-pull line without immediate damage.
This is a plug-in option card for Altivar drives — it mounts inside the drive housing, not on a DIN rail. The terminal connections accept 0.2 mm² to 0.5 mm² wire (AWG 24 to AWG 20), and the card draws 175 mA from the 15 V supply. Cable distance to the encoder can reach 500 m, but at that length the 1 kOhm input impedance and signal integrity need to be verified against the encoder's drive capability.