Configured for controller execution and safety-oriented logic processing in a ControlLogix architecture, the Allen-Bradley 1756-L72SK (1756-L72SK GuardLogix Controller) provides processor resources for I/O data handling and controller-level execution.

Model Identification

The 1756-L72SK is specified as a GuardLogix Controller within the ControlLogix family. The supplied data identifies 4 MB of user memory, 0.98 MB of I/O memory, and a maximum I/O capacity of 128,000 points. No additional suffix interpretation is established from the supplied information.

Hardware Specifications

ControlLogix Safety Controller Characteristics

The controller interfaces with the ControlLogix backplane and has a specified current draw of 800 mA at 5.1 VDC and 5 mA at 1.2 VDC. These values are relevant when determining chassis power loading.

The stated I/O capacity is 128,000 points, with up to 4,000 analog I/O points. The supplied specification also lists 128,000 maximum digital I/O points.

The specified 30 V continuous isolation voltage applies to the supplied controller specification. The available data does not define individual channel isolation, network isolation, or a specific galvanic isolation architecture.

Because the model is identified as a GuardLogix Controller, safety application configuration must be matched to the applicable GuardLogix system architecture, firmware, and safety configuration requirements. No specific SIL or PL rating is asserted here because it is not provided in the supplied data.

Ordering Information

• 1 x Allen-Bradley 1756-L72SK GuardLogix Controller
• 1 x Controller module corresponding to catalog number 1756-L72SK
• No separate chassis, communication adapter, or programming cable is specified in the supplied product information

Installation and Commissioning Notes

• Install the controller in a compatible ControlLogix chassis according to the applicable hardware installation procedure.
• Verify that available chassis backplane capacity accommodates the specified 800 mA current draw at 5.1 VDC.
• Include the stated 2.5 W power dissipation in chassis thermal calculations.
• Use appropriate ESD handling procedures when removing or installing the controller.
• Keep controller wiring and communication conductors separated from high-energy power conductors where practical.
• Verify controller firmware compatibility with the intended GuardLogix project before commissioning.
• Safety-related configuration should be validated using the applicable GuardLogix engineering and verification procedures.
• Do not assign an operating temperature range because none is provided in the supplied technical data.

Frequently Asked Questions

• What type of controller is the 1756-L72SK?

  The supplied product information identifies the 1756-L72SK as a GuardLogix Controller within the ControlLogix series.

• How much user memory is provided?

  The specified user memory capacity is 4 MB. This value should be considered when evaluating controller application and project memory requirements.

• What is the available I/O memory?

  The controller is specified with 0.98 MB of I/O memory for controller I/O data handling.

• What is the maximum I/O capacity?

  The supplied specification lists a maximum of 128,000 I/O points, including a maximum analog I/O capacity of 4,000 points.

• What is the 5.1 VDC current draw?

  The specified current draw is 800 mA at 5.1 VDC. Chassis power calculations should account for this load.

• What is the controller power dissipation?

  The supplied data specifies 2.5 W power dissipation and 8.5 BTU/hour thermal dissipation.

• What isolation voltage is specified?

  The controller is specified for 30 V continuous isolation voltage. The supplied data does not define channel-level isolation characteristics.

• Is the operating temperature range specified?

  No operating temperature range is included in the supplied information. A specific environmental limit should therefore not be inferred.