The 1785-L30B is an Allen-Bradley controller that belongs to the PLC5 controller family. This controller features 32Kwords user memory, Two (2) DH+/Remote I/O combination ports, configurable for Adapter or Scanner, One (1) serial port which supports RS-232, 423 and RS-422A communication standards. The 1785-L30B supports a large number of I/O devices. It supports up to 1024 I/O devices which may be composed of any combination of Discrete and analog input and output devices. Additionally, it also supports complementary 1024 input and 1024 output devices. Aside from the supports for large number of I/O devices, this controller is capable of implementing Remote I/O architecture as it may be connected to a maximum of 28 Remote I/O racks. For implementing Remote I/O architecture, the integrated communication ports such as DH+ and Remote I/O (RIO) channels may be utilized. Additionally, an Ethernet interface module may be added to implement the same architecture over Ethernet network. The 1785-L30B is installed with a battery that is used by the controller when power is removed from the controller. This battery maintains the user and program data stored within the controller’s user memory. It is assigned with a BATT indicator LED to report the current charge of the battery. For 1785-L530B, the battery can last up to 84 days when powered off at 100% and 150 days if Powered Off at 50% at an operating temperature of 60 Degree Celsius. When the BATT LED energizes, the battery remains operational for 5 days from the first occurrence of the signal. When the battery charge is completely drained, the contents of the user memory is maintained unless power is applied to the controller. It will only be erased when power is removed and battery is drained.