The Rockwell/Allen-Bradley 1764-28BXB is classified among the MicroLogix 1500 line. This series features programmable controllers whose parts are: processors, accessories and base units. This module is a base unit, that is meant to guarantee power supply to the CPU and additional modules (if present) and provide the user a set of integrated inputs and outputs. The device is powered with a 24 volts DC supply (the allowed range for the power voltage goes from 20.4 to 30 volts DC). The power consumption of the 1764-28BXB is below 30 watt (the actual power supply usage may be computed using the graphs on the product manual). This module provides 28 I/Os (16 inputs and 12 outputs) at the user disposal. The system’s inputs are 24 volts DC sink/source inputs. The outputs are divided into two groups: a set of 6 relay-based outputs and a set of 6 FET transistor outputs (with a 24 volts DC source). Despite having more I/Os with respect to the other Micrologix 1500 base units, the dimensions of the device are the same: 138 (H) x 168 (W) x 87 (D) millimeters. This base units is meant to be mounted horizontally. The user could expand the selection of I/Os using the Compact I/O expansion and mounting it on the right of the system. The engineer should allow 50 millimeters on all four sides (top, bottom, right and left) to provide the device proper ventilation. Applying excessive voltage to the base unit may result in danger and permanent damage to the device. Undervoltage or reverse wiring, instead, will not damage the unit (it may even not power up).

The 1764-28BXB is a base unit MicroLogix 1500 manufactured by the company known as Allen-Bradley. With sixteen (16), twenty-four (24) volt DC inputs, this base unit has twelve (12) FET/relay outputs. The device has a power supply rating of 24 volts DC. The line power rating for this base unit is 20.4 to 30 volts DC and a power supply inrush of 24 volts DC = 4 amperes for 150 milliseconds. The base unit does not feature a user power output. The input circuit type for this device is a sink/source, 24 volts DC circuit type, while the output circuit type is 6 relay, 6 FET transistors. For inputs eight (8) and higher, the On-state voltage ranges from 10 volts to 30.0 volts direct current, or DC, at 30 °C (86°F) or 10 volts to 26.4 volts DC at fifty-five (55) °C (131°F). The Off-state voltage range, however, ranges from zero (0) to five (5) volts. The minimum On-state current is 2.0 mA at ten (10) volts direct current, while the maximum On-state current is twelve (12.0) mA at thirty (30) volts DC. This Allen-Bradley MicroLogix 1500 base unit has an operating temperature that ranges from zero (0) to fifty-five (55) °C, or thirty-two (32) to one hundred and thirty-one (131) °F ambient. The temperature range recommended for storing this device is from -40 (negative forty) to 85 (eighty-five) degrees Celsius, or -40 (negative forty) to 185 (one hundred and eighty-five) degrees Fahrenheit converted, ambient. The humidity range recommended for this device's operation is from five percent (5%) to ninety-five percent (95%) relative humidity while also non-condensing. The operating vibration rating for the base unit is ten (10) to five-hundred (500) hertz, 5G, 0.015 inches. peak-to-peak, Relay Operation: 2G. The 1764-28BXB MicroLogix 1500 base unit has (UL 508, C-UL under CSA C22.2 no. 142, Class I, Div. 2, Groups A, B, C, D (ANSI/ISA 12.12.01, C-UL under CSA C22.2 no. 213), CE/RCM/EAC compliant for all applicable directives) certifications.