1756-L55M14 AB
About 1756-L55M14
Allen Bradley 1756-L55M14 is a ControlLogix 5555 controller. This series A controller has 3.5 MB of available data and logical memory, as well as 208 KB of I/O memory. It should be noted that the 1756-L55M14 controller does not have non-volatile memory.
The controller is placed inside the ControlLogix 1756 chassis and has an open housing. The controller itself weighs 0.36 kilograms or 12.8 ounces. Its battery can be replaced with a 1756-BA1 lithium battery. You should remember to replace the battery of the controller only when necessary. The only serial cable compatible with the 1756-L55M14 controller is the 1756-CP3 or 1747-CP3 cable.
This controller can support various communication modes, such as SynchLink, DH-485, Modbus via ladder router, universal remote I/O serial, Data Highway Plus, DeviceNet, ControlNet, and EtherNet/IP. As long as you pair it with the same controller and find it in the same ControlNet network, it can also be used for redundant systems. 
The backplane current in the 1756-L55M14 controller is 1.25 A at 5.1V DC and 0.14 A at 24V DC. Its power consumption is 5.7 W and thermal dissipation is 19.4 BTU/hr. The controller has been tested to withstand up to 707V DC for 60s, with a continuous isolation voltage of 30V, making it a basic insulation type. It has a conducted RF immunity of 10V rms and a 1 kHz sine wave of 80% AM from 150 kHz to 80 MHz.
