Serial interface for the MELSEC iQ-F backplane
The FX5-232-BD is a serial communication board that plugs directly into the MELSEC iQ-F series CPU module, adding one RS-232C port via a 9-pin D-sub male connector. It supports baud rates from 300 up to 115200 bps, selectable in standard increments, and handles both half-duplex and full-duplex communication — the full-duplex mode is what you need for a point-to-point link to a drive or HMI without toggling the line direction. Maximum transmission distance is 15 m, which is the RS-232C standard limit at 115200 bps — push the cable longer and you risk bit errors; keep it under 15 m and the link holds deterministic to the cycle.
Isolation — what it means for the control panel
The communication line is not insulated from the CPU module — that means the serial ground is referenced to the PLC logic common, not isolated by a digital isolator or optocoupler. In a panel with drives or inverters on the same serial link, this non-isolation means ground loops can inject common-mode noise into the CPU backplane if the cable shield is grounded at both ends. Best practice: ground the shield at one end only, or use an external isolated RS-232 converter if the run crosses a dirty cabinet boundary.
Active production — sourcing posture
No stock-holding claim — sourced per RFQ.