The PLC 1756-L55M22 is a ControlLogix Controller, a member of the Logix5000 series of controllers. It has 750 KB of data and logic memory, 208 KB of I/O memory, and an integrated nonvolatile backup memory. The 1756-L55M22 has 2 CPUs, a Logix and a backplane one, that divide its resources between them. Application codes and messages are executed by the Logix CPU, and the backplane CPU sends and receives data from the backplane and communicates with I/O.
The 1756-L55M22 controller is connected to a workstation or other controller via the serial port. The 1756-CP3 serial cable is used to connect the controller to the workstation. For communication with other devices, it uses various networks like Ethernet/IP, ControlNet, DeviceNet, etc. The 1756-L55M22 can produce and consume system-shared tags over the EtherNet/IP or the ControlNet networks. One connection each is required for both the producer and the consumer systems.The 1756-L55M22 controller has a multitasking feature which lets the processing time to be allocated to different operations in the application. It also contains programs for the group data and logic. It provides routines for encapsulating executable code in one programming language. It supports Logix5000 programming languages online and offline. In case of any I/O communication failure, it has an I/O LED that flashes green. It also contains a fault handler for diagnostics. The 1756-L55M22 supports the 1756-BA1 or the 1756-BATM battery which needs to be regularly maintained.
