The Allen-Bradley 1753-L28BBBM is a safety controller from a GuardPLC 1600 series. This is a safety controller with 28 I/O points. There are 8 non-isolated outputs and 20 non-isolated inputs integrated into it. This is a GuardPLC 1600 controller with Modbus communication. The Modbus communication can be used to exchange signal values and statuses with other systems. The 1753-L28BBBM itself is used to monitor for a fault or safety trip and then to revert all inputs and outputs affected to the “off” (current and voltage free) state. The “off” state or normally-open state is defined as the safe state.

This safety controller comes with 250 KB of user program memory and with 250 KB application data memory. Its operating voltage is 24 Volts DC (-15% to +20%) and it can consume up to 8 Amps of current. It has 4 RJ45 Ethernet connectors. The Allen-Bradley 1753-L28BBBM will react fast when the failure is detected. It only takes twice the cycle time of the system to perform safety operations. One cycle time of the system is a time needed to perform a reading of local inputs, to process the program, write local outputs, and to perform testing and communication routines. The Allen-Bradley 1753-L28BBBM is an IP20 protected device and its housing has dimensions of 257 millimeters (10.1 inches) x 114 millimeters (4.49 inches) x 66 millimeters (2.60 inches). The item’s weight is approximately 1.2 kilograms (2.64 pounds). Users can store the device at a -40 to 85 degrees Celsius (-40 to 185 degrees Fahrenheit) temperature range but use it only in a 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit) temperature range. The controller is certified by CE, C-Tick, and c-UL-us.