The 1756-L71S mainly features 2 MB standard user memory, 1 MB Safety memory, 0.98 MB I/O memory and 1 GB non-volatile memory provided by the pre-supplied 1784-SD1 that ships with the controller. Similar to standard ControlLogix controllers, the 1756-L71S has 1 USB communication port used for programming, hardware configuration and online editing. This controller is capable of handling up to 128,000 Discrete I/O points and 4000 Analog I/O points.
The 1756-L71S performs both standard and safety functions. Standard functions include I/O control, Logic, Timing, Counting, Report generation, Communication, Arithmetic computations and data file manipulation. Safety functions are communicated by the primary controller to the partner safety controller. The 1756-L71S does not support controller redundancy and programmed using programming languages such as Relay Ladder Logic (RLL), Structured Text, Function Block Diagram, Sequential Function Chart (SFC). For programming of safety task, only Relay Ladder Logix is permitted.
