The Allen-Bradley 1747-L40A is an SLC 500 series fixed type Programmable Logic Controller (PLC) hardware module. The unit has inbuilt I/O, computational processing unit (CPU) and memory. The modules comes equipped with twenty four (24) 120 volt alternating current input channels and sixteen (16) AC/DC relay output channels. The power supply requirements are 85 to 132 volts AC with a maximum off-state voltage of 30 Volts AC. The maximum turn-on time is 35 milliseconds and turn-off time is 45 milliseconds. The wires are #14 AWG in size that provide an I/O electrical-optical isolation of 1500 V AC at 60 seconds. The 1747-L40A has an operating temperature range of 32-140 degrees Celsius and a storage temperature range of -40 to 85 degrees Celsius. The PLC module memory is capable of taking 1024 instructions with a nominal input current of 12 milliamperes at 120 Volts AC.

The Random Access Memory is capacitor backed by default and can be upgraded to a battery back-up as well as memory recovery options such as Electrically Erasable Programmable Read Only Memory (EEPROM) and Ultraviolet Programmable Read Only Memory (UVPROM). The 1024 instructions have scan time of 8 milliseconds, with bit execution time of 4 microseconds and a scan hold-up time of 20 to 700 milliseconds in case of loss of power supply. Additional two (2) modules can be added to expand the I/Os and to cater to special / smart modules. The modules are secured in a 1746-A2 chassis and the hardware is panel mounted.

The Allen-Bradley 1747-L40A is equipped with several light-emitting diodes, or LED, indicators. These LED indicators include POWER, PC RUN, CPU FAULT, FORCED I/O, and BATTERY LOW. This device is also equipped with a NEMA Standard ICS 2-230 for noise reduction/immunity. Additionally, this device has statistics for displacement, acceleration, and duration. These three (3) statistics all have to do with vibration coming from this device. This product has a displacement of of 0.015 inch, peak to peak. This displacement comes at a 5 to 57 hertz frequency. The acceleration aspect of this device's vibration is 2.5 Gs at a 57 (fifty-seven) to 2000 (two thousand) hertz frequency range. The duration comes in at one (1) hour per axis (x, y, and z). This device has 0.27 watts per point. The minimum wattage of this device is 14.3 watts. The maximum wattage of this device is 23.0 watts. The typical battery life of these Allen-Bradley products usually last around five (5) years. The humidity range around this device when it is being stored should be maintained within the range of five (5) to ninety-five (95) percent. Additionally, the humidity range should be without condensation. 

The power supply operating voltage of this product is as follows: for AC units, 120 - 240 volts alternating current at 1.25 amperes and for DC units, 21.6 - 26.4 V DC (volts direct current), or 24 V DC (volts direct current) plus or minus 10 percent. The 24 volts direct current (VDC) user power output current is 200 milliamperes and the 24 volts direct current (VDC) user power output voltage is 20.4 - 27.6 volts direct current (24 volts direct current plus or minus 15 %).