COMPACT CPU 6ES7214-1BG40-0XB0 6ES7 214-1BG40-0XB0 6ES7214-1BG4O-OXBO

Siemens 6ES7214-1BG40-0XB0 | SIMATIC S7-1200 CPU 1214C AC/DC/Relay — 14 DI / 10 Relay DO / 2 AI / 150KB / PROFINET

AC/DC/Relay — The Version That Matters for Cabinet Design

The CPU 1214C is available in three hardware versions — DC/DC/DC, DC/DC/Relay, and AC/DC/Relay. The 6ES7214-1BG40-0XB0 is the AC/DC/Relay version, and all three elements of that designation have practical wiring consequences.

AC supply (85–264V, 47–63 Hz): The CPU draws power directly from single-phase AC mains — the same supply rail as other AC-powered panel components. No 24V DC power supply is needed for the CPU itself, simplifying the cabinet power distribution in installations where AC mains is the primary supply.

DC inputs (24V DC): All 14 digital inputs accept 24V DC sensor signals — proximity sensors, pushbuttons, limit switches, and relay contacts.

Relay outputs (2A): The 10 relay outputs switch loads at AC or DC voltages — contactors, solenoid valves, and pilot lights at the field voltage rather than through transistor-level signals. Relay outputs are electrically flexible: the same output card switches a 24V DC solenoid and a 230V AC contactor coil without interface hardware. The 2A per channel rating covers standard 24V DC relay coils (50–200mA) and 230V AC contactor coils (typically 15–100mA) directly.

Key Specifications

150KB Memory and Integrated Analog Input

The 150KB program/data memory covers the logic complexity typical of compact machine and panel-level automation — a typical machine control programme with 20 input conditions, 10 timer/counter sequences, and 12 output actions occupies 5–15KB; the 150KB provides ample headroom for complex sequences, data logging blocks, and communication function blocks simultaneously.

The 2 analogue inputs (0–10V DC) at the CPU level handle simple analogue measurement tasks — a speed reference potentiometer, a temperature sensor output, a pressure transmitter signal — without requiring an expansion analogue input module. For machines needing more than two analogue channels or 4–20mA current loop input, SM 1231 analogue expansion modules add capacity on the same CPU.

Replacement — Three Compatibility Checkpoints

For CPU 1214C replacement in an installed machine, confirm three elements before ordering: the hardware version (AC/DC/Relay), the onboard I/O count (14 DI / 10 relay DO / 2 AI), and the supply voltage class (85–264V AC). A CPU 1214C DC/DC/DC variant has the same memory and communication specifications but accepts only 24V DC supply and provides transistor outputs — the field wiring and output load compatibility differ fundamentally from the relay version.

FAQ

Q1: What makes the AC/DC/Relay version different from DC/DC/DC?

Supply and output type. The AC/DC/Relay accepts 85–264V AC mains supply; the DC/DC/DC requires 24V DC supply. Relay outputs switch AC and DC loads at field voltages; transistor outputs switch 24V DC only. In a cabinet designed around AC supply and relay-switched field loads, the AC/DC/Relay version is the correct match.

Q2: Can the relay outputs drive 230V AC contactors directly?

Yes. The relay outputs are rated 2A and switch AC or DC at field voltage. Standard 230V AC contactor coils draw 15–100mA — well within the 2A rating. Connect the relay output's common to the neutral and the NO contact to the contactor coil, with the live through the coil to the relay contact, following the cabinet wiring standard for the installation.

Q3: The CPU has 2 analogue inputs. Can more be added?

Yes. Siemens SM 1231 signal modules add analogue input channels (4 or 8 channels, 0–10V or 4–20mA) on the right side of the CPU via the S7-1200 expansion bus. The CPU 1214C supports up to 8 signal modules for analogue and digital I/O expansion.

Q4: What firmware version is this unit, and does it matter for existing projects?

This unit ships with firmware V4.7 — the current generation for the CPU 1214C. TIA Portal projects created for earlier firmware versions are generally compatible with V4.7 hardware. If the existing machine project specifies a minimum firmware version, confirm V4.7 meets or exceeds that requirement before installation.

Q5: Is the 6ES7214-1BG40-0XB0 the same as earlier CPU 1214C hardware revisions?

The -0XB0 suffix identifies the hardware revision — Siemens updates this for component-level changes while maintaining full software compatibility. Any hardware revision of the CPU 1214C AC/DC/Relay runs the same TIA Portal project without modification. The revision change does not affect the user's programme or configuration.