Allen-Bradley 1746-NO4V SLC 500 Analog Output Module

The Allen-Bradley 1746-NO4V, also cataloged as the 1746-NO4V analog output module, operates as a dedicated hardware component for voltage signal generation and analog loop execution within SLC 500 backplane-controlled I/O systems.

Suffix Breakdown & Model Matrix

The 1746-NO4V model is a single-part catalog identifier. No functional suffix segmentation or variant coding structure is defined for this module family.

Hardware Specifications

Backplane Output Execution Characteristics

The module performs synchronized DAC updates across four channels using cyclic backplane bus transfer. Output scaling is executed in fixed conversion intervals of 512 microseconds. Signal integrity is dependent on shielded field wiring and single-point ground termination due to absence of per-channel isolation. External 24 VDC supply supports field-side output driver stages independent of logic backplane rail.

Frequently Asked Questions (FAQ)

Q: Does the 1746-NO4V support individual channel isolation?
A: No. All four outputs share a common non-isolated architecture referenced to module common.

Q: Can the module be removed under live backplane operation?
A: The module does not support hot-swap. Removal requires SLC 500 rack power shutdown to avoid backplane disturbance.

Q: What is the effect of external 24 VDC supply loss?
A: Loss of external 24 VDC disables field output drive stages while backplane logic remains powered, resulting in zero output state.

Field Installation Guidelines

• Install module into SLC 500 chassis slot with full backplane connector engagement.

• Ensure rack power is isolated before insertion or removal.

• Use shielded cable (e.g., Belden #8761) for all analog output channels.

• Terminate cable shields at a single earth reference point only.

• Maintain separation between analog output wiring and high-frequency switching conductors.

• Verify terminal block locking before energizing system power rails.