The Allen-Bradley 1756 L72 is a ControlLogix Series Programmable Automation Controller (PAC). It has an available 4 MB user memory for data and logic and 0.98 MB I/O memory. The controller ships with a 1 GB SD card, the 1784-SD1, that you can use as optional nonvolatile memory storage. You can also upgrade it to 2 GB via the 1784-SD2 card if the storage is not enough for your use. It is recommended that the SD card is installed to the controller and to only use those that are sold by Rockwell Automation, as these cards have been fully tested to work with the controllers. Using other SD cards poses a risk of experiencing data loss or corruption. The SD cards are primarily used to store diagnostic data that is written automatically when a fault occurs. These data are used by Rockwell Automation for troubleshooting purposes. The 1756-L72 controller also comes with three capacitor energy storage modules. The 1756-ESMCAP/1756-ESMCAP is a removable module available in every controller. Another removable module is the 1756-ESM NSE/1756-ESM DEK that has no residual WallClockTime power backup. The only non removable module is the 1756-ESMNRM/1756-ESM RMK that helps prevent USB connection and SD card use to help secure the controller.
You can use the 1756-L72 controller together with specific modules to create an Armor ControlLogix controller. It can support controller redundancy when paired with a similar controller and in the same ControlNet network. ControlLogix chassis that are compatible with this controller are 1756-A4, 1756-A4K, 1756-A7, 1756-A7K, 1756-A10, 1756-A10K, 1756-A13, 1756-A13K, 1756-A17, and 1756-A17K. It also has 1 full-speed USB 2.0 port available and a 4-character alphanumeric display for you to view its current status. Several communication options are available with the 1756-L72 controller and these are Data Highway Plus, DeviceNet, Ethernet/IP, Remote I/O, SynchLink, ControlNet, and Third-party process and device networks. USB port connections are limited to configuration, on-line edits, programming, and firmware updates only. This controller has a continuous isolation voltage of 30 Volts and has been type tested for 60 seconds at 500 Volts AC. It has a current draw of 5 mA at 1.2 Volts DC and 800 mA at 5.1 Volts DC. Power dissipation of the 1756-L72 controller is 2.5 Watts and its thermal dissipation is 8.5 BTU/hour. Storage temperature of the controller ranges from -40 to 85 Degrees Celsius, while its operating temperature range is 0 to 60 Degrees Celsius. It has a vibration of 2 G at 10 to 500 Hertz, an operating shock of 30 G, and a non-operating shock of 50 G.
The Allen-Bradley 1756-L72 belongs to the most recent ControlLogix product category. This part number represents a ControlLogix controller with 4Mb user memory and pre-allocated I/O memory capacity of 0.98 MB.
The 1756-L7x Controllers introduced several upgrades. For the non-volatile memory, this controller used Secure Digital (SD) cards. By default, this controller is shipped with a 1GB non-volatile memory. Replacement modules for this non-volatile memory are 1756-SD1 and 1756-SD2. Additionally, this controller does not use batteries. Instead of an RS232 communication port, this controller has a USB communication port that functions similar to the RS232 however, is more robust and does not require expensive communication cables. Furthermore, aside from RSLogix 5000 programming software, this controller supports Studio 5000 Logix Designer, the rebranded version of RSLogix 5000. For 1756-L72 with firmware of Version 21.00.00 or later, use Studio 5000. For Firmware Version of 19.01.00 or later use RSLogix 5000. If required, the controller’s integrated memory may be upgraded or downgraded with the use of the Flash utility tool.
This controller has Front Panel Display that continuously prompts the Devices Status, Operating Mode and other diagnostics. The operating Mode is changeable with the use of a supplied key, small form factor occupying only a single slot of the 1756 Chassis and an easily attachable/ Detachable module.
This Programmable Automation Controller (PAC) is OPC UA compliant which enables a much easier configuration to the control and data network. It also supports communication protocols such as Ethernet I/P; ControlNet; DeviceNet; Data Highway Plus; Remote IO; Synchlink; Third party process and device networks.