1756-L71S

The Allen-Bradley 1756-L71S is a GuardLogix 5570 controller that is a part of the Logix5000 family of controllers. It is a ControlLogix controller with safety features. It is a dual processor solution which must be used with a 1756-L7SP safety module to meet SIL 3 or Cat. 4/PLe safety standards. The safety partner controller is automatically configured, providing major benefit being a single project. It has great processing capabilities and speed for motion and high-performance logic. It has a USB port for communication and it can support up to 500 controller connections. The 1756-L71S controller has 2MB of user memory, 1MB Safety Memory, and 0.98MB of I/O memory. It can support 128,000 digital I/O and 4000 Analog I/O. It draws a current of 5mA at 1.2V DC and 800mA at 5.1V DC. Its power dissipation is 2.5W and its thermal dissipation is 8.5 BTU/hr. It weighs 0.55lbs and has an isolation voltage of 30V (continuous) for basic insulation. It can be installed in any slot in a ControlLogix 1756 Chassis. For safe communication, it uses ControlNet, DeviceNet, or EtherNet/IP networks. The 1756-L71S controller can control or monitor I/O over the backplane or through I/O links. For controller diagnostics, it has a front display that provides runtime information. It functions using the 1756-ESMCAP and the 1756-ESMCAPK Energy Storage Module, which means that lithium batteries are not needed. A 1 GB (1784-SD1) Secure Digital card comes pre-installed as an optional non-volatile storage which can be expanded up to 2 GB (1784-SD2).

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. Safety communication options supported by the 1756-L71S includes Ethernet I/P, ControlNet and DevideNet. If used with 1756-CN2/A, 100 ControlNet connections is supported, 40 with 1756-CNB/D, 1756-CNB/E, and 128 with 1756-CN2/B. For Ethernet, 256 EtherNet/IP; 128 TCP connections is allowed using 1756-EN2x and 128 EtherNet/IP; 64 TCP with 1756-ENBT.