Earlier this month the widely used ControlLogix Ethernet module, part number 1756-ENBT, had it's status updated to “end of life” on Rockwell's Product Lifecycle Status page.
The product is now listed as going out of production in roughly 18 months, on December 31st, 2016.
The seemingly logical choice to replace the 1756-ENBT would be the newer and more capable 1756-EN2T.
Compared with the ENBT’s 64 TCP & 128 CIP connections, and 5000 I/O Packets per second limit, the EN2T is far superior with 128 TCP & 256 CIP connections, as well as supporting between 10,000 and 25,000 I/O Packets per second.
All versions of this newer module include a USB port for access to the module's own configuration, as well as to the rest of the ControlLogix system.
This allows programming and configuration of interconnected devices, including the EN2T's own Ethernet address.
The EN2T includes other enhancements over the ENBT, with one of the most versatile being Open Sockets support.
With a free AOI from Rockwell’s sample code website, users can quickly enable Modbus TCP communications over the EN2T using the open sockets feature.
On the down side, the 1756-EN2T currently carries a published list price 20% greater than the ENBT, which itself has seen a 20% price increase over the last few years.
And the EN2T, with it’s substantialy larger connection limit and packets per second rating, seems a little over powered for smaller systems or when used as a remote Ethernet I/O adapter.
Hopefully Rockwell realizes this and will release a new lower cost and lower functionality Ethernet module prior to the ENBT’s last day of production.
I hope you found the above article about the ENBT's end of life announcement helpful.
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