The Allen-Bradley 1757-SRM ControlLogix redundancy module provides an enhancement to redundancy system components by synchronizing, locking, and maintaining the communication between redundant chassis pair without additional programming. This Allen-Bradley 1757-SRM ControlLogix redundancy can be supplied from 1756-PA75R or 1756-PB75R power supplies with a current draw of 1 ampere and power consumption of 11.28 watts. The 1757-SRM ControlLogix redundancy module can be connected to the redundant chassis pair through an SC-type fibre-optic wire that offers a wavelength of 1300 nanometers. The module can be employed in several applications mainly in the industrial field. The 1757-SRM module can be mounted and installed easily on a ControlLogix chassis at any place. The Allen-Bradley 1757-SRM ControlLogix redundancy module dissipates an electrical power of 11.28 watts and a thermal power of 38.49 british thermal units per hour.
This Allen-Bradley 1756 ControlLogix redundancy module uses 1757-SRCxxx wires. This ControlLogix redundancy module offers to a redundant system a high data rate speed. The 1757-SRM ControlLogix redundancy module includes a status display of 4 characters to show the diagnostic information, a chassis status LED indicator that indicates the module state, a communication status LED indicator and a health status LED indicator that simplifies the maintenance and troubleshooting process. The 1757-SRM ControlLogix redundancy module is intended for use in a mainly industrial environment that is clean and dry. This hardware works properly at 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit) for industrial applications and weighs approximately 0.452 kilograms (0.99 pounds) while shipping.

The 1757-SRM is a system redundancy module made by Allen-Bradley. It is compatible with the ProcessLogix and ControlLogix product families. This module is used to provide controller redundancy to increase the process system availability and to ensure continuous operation for critical industrial processes that must not be stopped under any circumstances. An identical secondary PLC operating on a separate ControlLogix chassis is synchronized with the primary unit. The size of the chassis installed modules and their positions, module revisions, and system power supply need to be identical for the system to be redundant. In case of a primary PLC system failure, the secondary unit assumes control and alerts the user without interrupting the ongoing process. The modules are connected via a 1757-SRCxx Fiber-optic Cable that uses an SC connector. The cable-type is multi-mode 62.5/125 micron and multiple cable length options are available ranging from 1 meter (3 feet) in length up to 100 meters (300 feet). The module includes an integrated Fiber Optic port to allow for cable connection. The 1757-SRM occupies two slots in the chassis. This module features an LED display that indicates the module’s operational status. One LED is used to show the device's Health status, indicating normal operation, self-test, or failure modes. Communication and synchronization status is shown by the COM LED. The primary controller is identified using the PRI LED. Upon startup, the 1757-SRM module checks the connected systems to ensure the required systems are compatible and identical to establish a redundant system.