1756-L55M16

The Allen-Bradley 1756-L55M16 is a ControlLogix Controller, a part of the Logix5000 series of controllers. It has 7.5 MB of data and logic memory and 208 KB of I/O memory. It has a Logix and a backplane CPU to divide its resources between them. The application code and messages are executed by the Logix CPU and the backplane CPU sends and receives data from the backplane and communicates with the I/O. The 1756-L55M16 controller is connected to a workstation or another controller via the serial port. A 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-L55M16 can broadcast and receive system-shared tags over the EtherNet/IP or ControlNet networks. One connection each is required for both producer and consumer. The 1756-L55M16 controller has a multitasking feature which lets processing time be allocated to different operations in the application. It also contains programs for group data and logic. It provides routines for encapsulating executable code in one programming language. It supports Logix5000 programming languages both online and offline. In case of any I/O communication failure, it has an I/O LED that flashes green. The 1756-L55M16 also contains a fault handler for diagnostics. It supports the 1756-BA1 or the 1756-BATM battery which needs to be regularly maintained.