Allen Bradley SLC 500 1746-NIA 1746-N1A Date Varies. Surplus Unit Working Used 1746-NI4 Ser A 1746-N14 1746NI4 1746-NI4/A. While many Allen Bradley / Rockwell Automation products will have firmware already installed, we makes no representation as to whether a PLC product will or will not have firmware and, if it does have firmware, whether the firmware is the revision level that you need for your application or not.
