How It Sits Against a Sibling
The E5CC-QX2ASM-800: Compared to the Omron E5CC-CX3A5M-004, the core input range, supply voltage, cutout, and IP rating are identical—both fit the same 45x45mm panel hole and run on 100-240VAC. The CX3A5M-004 adds RS-485 communications (CompoWay/F, Modbus) and an event input, plus one analog output alongside three relays; this seed lacks comms and event input entirely. If your application logs temperatures or coordinates with a PLC over Modbus, you need the CX3A5M-004. If all you need is a standalone PID controller driving an SSR and two alarms, the QX2ASM-800 is cleaner and costs less. Physical fit is identical: same screw terminal layout and same mounting depth for the E5CC family. Another active sibling, E5CC-RX3A5M-003, adds heater fault detection via a CT input and four relays (one spare). The seed has no CT input capability. Again, same panel cutout, same supply, so a mechanical swap is possible if wiring is adjusted for the additional relay outputs.