The 6ES72121BG500XB0 is a Siemens CPU 1212C with relay outputs and an Ethernet port. It runs on 24 V DC and snaps onto a DIN rail. This is the active order code for the basic compact PLC that handles digital control with relay switching. Relay outputs allow switching dry contacts. The Ethernet port handles program downloads and S7 communication; this CPU is not a PROFINET IO device or controller.
Siemens 6ES72121BG500XB0 CPU 1212C, Relay, Ethernet
MPN6ES72121BG500XB0
Siemens CPU 1212C, 6ES72121BG500XB0, Programmable Logic Controller, Relay Output, Ethernet, 24 V DC, DIN Rail.
StockContact for availability
MOQ1 pcs
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
How we verify every order →Specifications
| Parameter | Value |
|---|---|
| Output signal | Relay Output |
| Interface | Ethernet |
| Supply voltage | 24 V DC |
| Is profinet IO device | false |
| Is profinet IO controller | false |
| Mounting fastener | DIN Rail |
Product details
Frequently asked questions
What replacement or second source exists for 6ES72121BG500XB0?
The order code 6ES7212-1BG50-0XB0 is functionally identical—same CPU, same relay outputs, same Ethernet, same power supply. It's a different catalog number but the same physical part. Both are interchangeable in a panel without rewiring.
What are the key specs of this PLC?
Output type: relay. Interface: Ethernet (not PROFINET IO device/controller). Supply voltage: 24 V DC. Mounting: DIN rail. It's a Siemens CPU 1212C.
Does it drop into a panel designed for the older order code 6ES7212-1BG50-0XB0?
Yes, the form factor, mounting, and electrical connections are identical. No modification to the panel or wiring is needed.
MPN
6ES72121BG500XB0