What the NJ501-4320 is
The OMRON NJ501-4320 is an NJ5-series machine-controller CPU with built-in Robotics functionality and SQL database connectivity — it is not a standard logic controller but a controller designed for applications that need to command motion and query or log to an SQL back-end simultaneously. The Robotics designation means it carries the motion-control instruction set and positioning handling that a bare NJ5 logic CPU does not; the SQL stack means it can execute database transactions directly from the control program without a separate gateway or OPC server.
Same series as NJ501-1340 — does it drop in?
The NJ501-1340 shares the same series designation and the same Bulk package as the NJ501-4320, which suggests mechanical and mounting compatibility at the DIN-rail or chassis level. However, the NJ501-4320 carries the Robotics & SQL functional designation that the ledger does not attribute to the NJ501-1340 — they are siblings in the same series, not identical units. Before substituting one for the other on a frozen BOM, confirm that the Robotics instruction set and SQL stack are not called by the application program on the NJ501-4320, or the replacement will run but not execute the motion or database operations the machine depends on.