The Allen-Bradley 1756-L75 (1756L75 Logix5575 Processor) executes controller logic and manages ControlLogix I/O and controller communications through its backplane and configured network connections.

Model Identification

The supplied catalog references identify the processor as part of the ControlLogix Logix5575 controller family.

• Catalog Number: 1756-L75
• Alternate Model Reference: 1756L75
• Product Type: ControlLogix Logix5575 Processor
• Series: ControlLogix
• Processor Family: Logix5575
• User Memory: 32 MB
• I/O Memory: 0.98 MB
• USB Port: 1
• Controller Connections: 500
• Display: 4-character alphanumeric display

Processor Specifications

ControlLogix Processor Architecture

The 1756-L75 operates as the controller processor within a ControlLogix chassis. It executes the application program and manages data exchange with configured I/O and communication resources.

The processor provides 32 MB of user memory and 0.98 MB of I/O memory according to the supplied specifications. Its 4-character alphanumeric display provides local processor status information.

The stated controller connection capacity is 500 connections. Actual network loading and connection usage depend on the configured ControlLogix architecture and connected devices.

Backplane and Network Characteristics

The processor is installed in a ControlLogix chassis and uses the chassis backplane for communication with compatible modules. The supplied electrical data specifies 5 mA at 1.2 VDC and 800 mA at 5.1 VDC.

EtherNet/IP connectivity and deterministic network behavior depend on the communication modules and network architecture used with the processor. The supplied information does not specify a native Ethernet port on the 1756-L75 itself.

Ordering Configuration

• 1 x Allen-Bradley 1756-L75 ControlLogix Logix5575 Processor
• ControlLogix chassis and separate communication modules are not specified as included.
• Programming cables, terminal accessories, and network modules are not included unless separately specified.
• Any required chassis, power supply, communication module, and programming interface should be selected according to the installed system configuration.

Field Installation Notes

• Install the processor in a compatible ControlLogix chassis with the appropriate chassis power supply.
• Confirm the processor slot position and chassis configuration before energizing the system.
• Maintain physical separation between communication wiring and high-voltage power conductors.
• Connect the processor and associated modules according to the applicable ControlLogix wiring and grounding requirements.
• Use the processor display for local status indication during commissioning and fault diagnosis.
• Verify controller memory requirements before transferring the application program.
• Do not assume that a communication protocol is provided directly by the processor when a separate communication module is required.

Frequently Asked Questions

• What is the 1756-L75?
  The 1756-L75 is an Allen-Bradley ControlLogix Logix5575 processor used to execute controller logic and manage configured ControlLogix system operations.
• How much user memory does it provide?
  The supplied specifications list 32 MB of user memory for the 1756-L75 processor.
• What is the stated I/O memory capacity?
  The supplied product data specifies 0.98 MB of I/O memory.
• How many controller connections are specified?
  The supplied information specifies a maximum of 500 controller connections.
• Does the processor have a USB port?
  Yes. The supplied product information identifies a USB port on the 1756-L75 processor.
• Does it have a local display?
  Yes. The processor is specified with a 4-character alphanumeric display for local status information.
• What are the stated backplane current values?
  The supplied data lists 5 mA at 1.2 VDC and 800 mA at 5.1 VDC.
• Is the operating temperature specified here?
  No operating temperature range was included in the supplied information, so a numerical temperature range is not assigned.