Allen-Bradley 1746-NO4I SLC 500 Analog Output Module 4-Channel Current

Product Introduction

When precise current output signals are required to drive modulating instruments in industrial control systems, the Allen-Bradley 1746-NO4I delivers reliable performance. This analog output module belongs to the SLC 500 product platform and works with both fixed and modular controller hardware styles. With four current output channels, it converts digital control commands into analog signals for valves, actuators, and other field devices.

Technical Specifications Breakdown

The 1746-NO4I provides four current outputs with a range of 0 to +20 mA and a full-scale output of 21 mA. Its overrange capability reaches 5% (0 to +21 mA minus 1 LSB), giving operators a small margin above the nominal range. The module uses 14-bit resolution via the R-2R ladder conversion method, ensuring fine granularity in output signals. Update time is 512 microseconds for all channels in parallel, while step response reaches 95% in 2.5 milliseconds. Backplane current draw is 55 mA at 5 Volts DC and 195 mA at 24 Volts DC. Operating temperature range is 0 to 60 degrees Celsius.

Industry Applications

In process control environments, the 1746-NO4I connects to PID controllers to represent the control output (CO) signal. This allows precise regulation of flow, pressure, or temperature loops. For manual loading stations, the module outputs the operator-entered manual command. It also serves signal retransmission tasks, sending an important process variable to data loggers, indicators, or other devices. The 0 to +20 mA range is standard for many industrial instruments, making integration straightforward.

Installation & Setup Guidance

Mount the 1746-NO4I in any 1746 chassis. Use shielded communication cable such as Belden 8761 or equivalent, keeping cable lengths as short as possible to minimize noise. The module includes a removable terminal block for simplified wiring and easy replacement. An embedded selector switch allows choosing between internal backplane power or an external 24 Volts DC supply (24 ±10% at 195 mA max). Configure the output signal type and range through the module properties in your programming software.

Maintenance & Reliability

The 1746-NO4I is factory-calibrated and housed in an open enclosure. Its LED status indicator provides quick visual feedback on module health. To ensure long-term accuracy, inspect the module periodically for dust or debris that could affect airflow. The ambient operating temperature range of 0 to 60 degrees Celsius covers most industrial environments. With no moving parts and solid-state outputs, this module offers reliable service in continuous-duty applications.

Selection Guide & Purchasing Advice

Before purchasing, verify that your SLC 500 system has an available slot in the 1746 chassis and sufficient backplane power capacity (55 mA at 5 VDC and 195 mA at 24 VDC per module). The 1746-NO4I is compatible with both fixed and modular SLC 500 controllers. For applications requiring 21.6 to 26.4 Volts DC power, ensure your external supply meets the 24 Volts DC +/-10% specification at 195 mA maximum. BluePLC Industrial stocks this module and can assist with availability and ordering.