What it is and where it sits
The Mitsubishi FX3S-CNV-ADP is the FX3S series adapter accessory, listed as an industrial computer board under the PLCs and Accessories class. It is the small option/adaptation board that drops into a Mitsubishi FX3S base PLC to extend or convert the local interface, not a stand-alone CPU.
Lifecycle and the RFQ posture
Specify FX3S-CNV-ADP into the BOM as a line-down spare; we quote to order against an RFQ. Pricing and availability come back on the quote, not the page.