Emerson VE4002S2T2B8 DeltaV Discrete Output Card

The Emerson VE4002S2T2B8, also cataloged as the VE4002S2T2B8 Discrete Output Card, operates as a dedicated hardware component for solid-state switching of actuator loops within DeltaV distributed control system platforms.

Hardware Specifications

High-Side Power Switching & Galvanic Isolation

The card executes high-density digital control operations via independent output circuits optimized for industrial actuators.

• High-Side Switching Topology: The module switches the positive leg of the 24 VDC field circuit power supply to the load, preventing accidental load activation in the event of a field wiring ground fault.
• Optical Isolation Barriers: Individual optical couplers isolate each channel's field side circuitry from the internal 12 VDC LocalBus up to 1500 VDC, preventing electromagnetic noise and transient voltage spikes from disrupting backplane logic.
• Thermal Protection limits: Integrated solid-state output drivers automatically limit current during overtemperature or short-circuit faults on the field loops, protecting the internal trace paths of the module from thermal damage.

Frequently Asked Questions

Q: What is the maximum current capacity of the VE4002S2T2B8 card if all 32 channels are activated simultaneously?

A: Although individual channels can drive up to 1.0 A, the entire card is limited to a total field circuit power throughput of 3.0 A. Load distributions must be engineered so that the cumulative active current does not exceed this 3.0 A boundary.

Q: Does the module require an external 24 VDC source to power the output loads?

A: Yes. The LocalBus only powers the internal logic and optical couplers of the module. All 32 high-side output channels require external field power supplied through the matching 32-channel terminal block.

Q: How does off-state leakage current affect high-impedance field devices?

A: The off-state leakage current is 1.2 mA maximum. For ultra-low power solenoid valves or high-impedance relays, this leakage current may prevent the device from dropping out. An external bleed resistor must be installed in parallel with such loads to shunt the leakage current.

Field Installation Guidelines

• Module Pin Alignment: Prior to inserting the card into the carrier slot, inspect the rear connector keys to ensure they align perfectly with the backplane socket before pressing down on the locking tab.
• Terminal Block Compatibility: Always pair the VE4002S2T2B8 card with the standard 32-channel discrete output terminal block designated for Series 2 Plus architectures.
• Shield Grounding Conductors: Connect the shield wires of all digital output field cables to the designated ground bus on the DeltaV carrier to minimize electromagnetic radiation.
• Ventilation Clearance: Maintain at least 50 mm (2.0 in) of free space above and below the carrier rack to ensure natural convection cooling under high-ambient temperature conditions.