The 1756-L61 is a ControlLogix controller manufactured by Allen Bradley/Rockwell Automation as part of the Allen Bradley ControlLogix series, which is available in Series A and B. The 1756-L61 controller has a current draw of 14 milliamps at 24 volts DC and 1200 milliamps at 5.1 volts DC. It has a power dissipation of 3.5 watts and thermal dissipation of 11.9 BTU per hour. This module features a continuous isolation voltage of 30 volts, tested at 720 volts DC for one minute. This is a chassis-based controller that can be placed in any slot of the 1756 ControlLogix chassis. Note that 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17 are the only chassis available for the 1756-L61 controller. It features an open enclosure type and can support a maximum connection of up to 250 controllers. This module comes with an inbuilt RS-232 serial communication port with DF1 serial port communication full/half-duplex, DH-485, DF1 radio modem, ASCII, and Modbus via logic. Allen Bradley 1756-L61 controller comes with maximum analog I/O of 4,000, maximum digital I/O of 128,000, and maximum total I/O of 128,000. This controller’s tasks include 32 tasks, 100 programs per task, as well as event tasks that are all event triggers. The 1756-L61 controller features various communication options, including Data Highway Plus, Remote I/O, ControlNet, DeviceNet, EtherNet/IP, SynchLink, as well as third-party process and device networks. It has an operating temperature of 0 – 60 Degrees Celsius, a storage temperature of -40 to 85 Degrees Celsius, and 60 Degrees Celsius maximum surrounding air temperature. It has a non-condensing relative humidity of 5 – 95 percent. It features a 2-megabytes user memory as well as 478 kilobytes input and output memory and an optional 128 megabytes of non-volatile storage memory. Still, the user can use the 1784-CF128 CompactFlash memory card.

The 1756-L61 is a type of chassis-based controller. It belongs to the ControlLogix line of controllers from Allen-Bradley. This controller is compatible with the 1756-A7, 1756-A4, 1756-A10, 1756-A17, and 1756-A13 chassis controllers. It comes equipped with two (2) megabytes (MB) of user memory and four hundred and seventy-eight (478) kilobytes (kb) of I/O memory. It also comes pre-installed with one hundred and twenty-eight (128) megabytes (MB) of non-volatile memory which should be installed on the embedded CompactFlash card. It should be housed inside an open-style enclosure.

This controller supports a maximum of 250 connections. For communication, this controller comes equipped with the RS-232 port. This serial port is compatible with the following communication protocols - ASCII, Modbus via logic, DF1 radio modem, DF1 full/half-duplex, and the DH-485. Furthermore, this controller supports a wide array of connectivity options starting with the Data Highway Plus, ControlNet, Ethernet/IP, SynchLink, DeviceNet, and the Remote I/O. Furthermore, it is compatible with many third-party communication devices. 

It comes equipped with a total I/O rating of 128,000 digital I/O rated at 128,000, and an analog I/O rated at 4,000. This controller can complete a total of 32 tasks. Each of these tasks can accommodate 100 different programs. The event triggers are programmed as event tasks. For power, this controller must be supplied with 5.1 volts direct current (DC). At 24 volts direct current (DC), the current draw rating for this controller is 14 milliamperes. Its power dissipation is rated at 3.5 watts. The thermal dissipation rating for this module is 11.9 BTU/hr. It can absorb an operational shock of 30 G, and a non-operational shock of 50 G.