Allen‑Bradley 1756-L73K

The 1756-L73K is an 8MB ControlLogix 5570 controller, conformal coated version of standard 1756-L73. The suffix K stands for conformal coating, protecting PCB circuits against humidity, dust, corrosive gas and condensation for harsh cabinet environments. This 1756-L73K features 8MB user memory, supports up to 100 CIP motion axes for Kinetix servo drives, compatible with 1756 ControlLogix rack backplane.

This 1756-L73K comes with one USB programming port, no built-in Ethernet port; Ethernet communication needs external 1756-ENBT / 1756-EN2T modules. It supports hot-swap, redundant control configuration with 1756-RM2 redundancy module. Program download, logic editing and fault diagnosis are completed via Logix Designer software. It uses SD card for non-volatile program backup, and 1756-ESMCAP capacitor for memory retention during power loss. Status LEDs display run, fault and communication state for fast troubleshooting. It complies with CE, UL, ATEX and IECEx certifications.

The 1756-L73K is widely deployed in power plants, oil & gas, chemical and mining control systems where high humidity or corrosive atmosphere exists. The 5570 series is mature and still available for order. Many automation maintenance teams stock the 1756-L73K as spare CPU for harsh-condition control rack overhaul and emergency replacement.