If you must use the Rack Optimized communication format, we recommend that you place the 1756-EN2TR or 1756-EN2TRXT module in a separate chassis from the 1756-ENBT module. Do not upgrade the firmware for more than one module simultaneously through the USB port., When a 1756 Discrete Output Module utilizing a Rack Optimized connection in a remote chassis establishes a connection, outputs will briefly transition to a random non-commanded state., Sign in to your Rockwell Automation account to view and download technical drawings. Find curated technical documentation for this product in the Technical Documentation Center, or search our full Literature Library. This product was certified with the above certifications as of 2025-06-15., These release notes describe version information for 1756-EN2F Signed, version 5.029 (released 6/2023). This release includes the following system features. Improved Product Resiliency for ControlLogix® EtherNet/IP™ Communications Modules. Product improvements have been made to increase product resiliency to potentially disruptive activities., When you install the digitally signed firmware, that is, firmware revision 5.029, into a 1756-EN2T/C (or earlier), 1756-EN2TR/B (or earlier), or 1756-EN2F/B (or earlier) module, the installation makes the module incompatible with some firmware revisions., Answer 1715-AENTR v1.5.0 works with the following ControlLogix Ethernet modules and firmware: 1756-EN2T v4.003 and latter 1756-EN2TR v4.003 and latter Notes: Other Firmware versions may work, but they have not be completely functionally tested with 1715-AENTR 1756-ENBT version 3 and early do not work with the 1715-AENTR.