Allen-Bradley 1746-NO8V SLC 500 Analog Output Module

The 1746-NO8V is an 8-channel analog voltage output module for the SLC 500 PLC platform. Each channel provides a 0 to 10 VDC signal with 12-bit resolution (0.00244 V per LSB). The module is used to control proportional valves, variable frequency drives, chart recorders, and other analog actuators. It occupies one slot in the SLC 500 chassis and is compatible with all SLC 5/01, 5/02, 5/03, 5/04, and 5/05 processors.

Electrical Specifications

• Number of Outputs: 8, single-ended

• Output Range: 0 to 10.5 VDC (overrange capability)

• Resolution: 12 bits (4096 counts)

• Accuracy: ±0.2% of full scale at 25°C, ±0.5% over full temperature range

• Update Rate: 4 ms per channel (32 ms for full scan)

• Output Load: Minimum 2 kΩ (maximum current 5 mA per channel)

Protection and Diagnostics

Each output is short-circuit protected (current limited to approximately 20 mA) and has an open-wire detection feature. The module provides a green OK LED for power/status and red LEDs for per-channel fault indication. An external 24 VDC power supply is required for the output circuits; the module draws 200 mA from the backplane 5V bus and 150 mA from the 24V user supply.

Calibration and Configuration

The 1746-NO8V is factory calibrated, but field calibration can be performed using a voltmeter and Rockwell Automation's software. Calibration constants are stored in non-volatile EEPROM. Configuration is done via the SLC processor's I/O configuration word, selecting data format (raw/proportional) and enabling/disabling per-channel open-wire detection. The module also supports electronic keying to prevent mismatched replacement.

Physical and Environmental

Dimensions: 143 mm × 87 mm × 92 mm (H × W × D). Weight: 0.3 kg. Operating temperature: 0 to 60°C; storage: -40 to 85°C; humidity: 5–95% non-condensing. Vibration: 2.5g at 10–500 Hz. The module meets UL 508, CSA C22.2, and CE (EMC) standards. Removable terminal block (RTB) is supplied with screw clamps for 14–22 AWG wire.

Applications

Commonly deployed in plastic extrusion lines (temperature control via valve actuation), water treatment (chemical dosing), and conveyor systems (speed reference to drives). For higher channel density or current outputs, consider 1746-NO4I or 1746-NO8I. The module is also compatible with the SLC 500 remote I/O adapter (1747-ASB) in distributed configurations.