Siemens 6ES7214-1BG40-0XB0 — CPU 1214C AC/DC/Relay Buyer's Guide

By Abdullah Zahid
12 min read
Siemens 6ES7214-1BG40-0XB0 CPU 1214C AC/DC/relay compact PLC for machine and process automation

Siemens 6ES7214-1BG40-0XB0 — SIMATIC S7-1200 CPU 1214C AC/DC/Relay: Complete Specifications, Alternatives and Selection Guide

When a controls engineer searches for the Siemens 6ES7214-1BG40-0XB0, they are almost always at the same decision point: confirming that the onboard I/O count, relay output rating, and AC power supply match the machine in front of them before committing to a purchase. This is the SIMATIC S7-1200 CPU 1214C AC/DC/relay — a compact PLC CPU that integrates 14 digital inputs, 10 relay outputs rated at 2 A per contact, and 2 analog inputs into a 110 x 100 x 75 mm housing, powered directly from AC 85-264 V without a separate power supply module. If you are evaluating this SKU for a conveyor, packaging line, HVAC control system, or any small-to-medium automation task, this guide covers every specification, variant comparison, and procurement detail you need to make a confident decision.

If you have already confirmed this is the right part, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the 6ES7214-1BG40-0XB0 — and Who Shouldn't

This CPU is the right choice when your application fits within a clearly defined I/O envelope and your installation panel runs on AC power. Buy this part when all of the following are true:

  • Your application requires no more than 14 digital inputs and 10 digital relay outputs onboard
  • Your panel supply is AC 85-264 V at 47-63 Hz — not DC-only
  • Relay switching at 2 A per output covers all load types in your system
  • A single PROFINET RJ45 port is sufficient for your network topology
  • Your engineering environment runs STEP 7 V20 or higher (TIA Portal)
  • Installation site temperature stays within -20 to 60 degrees C and altitude does not exceed 5000 m

If your application requires analog outputs, choose the 6ES7214-1HG40-0XB0 instead. If you need a DC-only supply, the 6ES7214-1AF40-0XB0 is the correct variant. If your I/O count significantly exceeds the onboard capacity of this CPU, step up to the CPU 1215C or CPU 1217C within the SIMATIC S7-1200 family.

On this page:

What the 6ES7214-1BG40-0XB0 Actually Does in a Control System

The 6ES7214-1BG40-0XB0 is the central processor of a SIMATIC S7-1200 control system. It executes STEP 7 logic programs stored in its 150 KB combined program and data memory, manages I/O scanning, handles PROFINET communication, and runs integrated function blocks for positioning, high-speed counting, and PID control — all without requiring a separate CPU rack or dedicated I/O chassis.

What sets the CPU 1214C AC/DC/relay apart from bare-bones micro-PLCs is the density of its integrated functions. The 6 high-speed counter inputs, capable of counting at up to 100 kHz, handle encoder feedback or pulse measurement tasks that would otherwise require a dedicated counter module. The built-in support for up to 8 controlled positioning axes — expanding to 4 pulse-direction axes with the SB 1222 signal board — means that small pick-and-place machines or multi-axis gantries can be controlled from this single CPU without an external motion controller. The hardware real-time clock, backed up for 480 hours, ensures timestamped logging and scheduled operations survive power interruptions for roughly 20 days.

The relay output design is a deliberate choice, not a limitation. Relay contacts rated at 2 A per output and 10 million mechanical cycles can switch AC or DC loads directly — fans, pumps, solenoid valves, small contactors — without an intermediate relay bank. The SIMATIC S7-1200 family has been deployed in over 1 million installations globally since 2012, with typical field longevity exceeding 10-15 years in manufacturing and process automation environments, which reflects the platform maturity engineers are relying on when they spec this CPU.

Typical System Architecture for the CPU 1214C AC/DC/Relay

The 6ES7214-1BG40-0XB0 sits at the top of the local control chain, acting as both the execution engine and the primary PROFINET node connecting the machine to supervisory systems or distributed I/O.

  • AC mains supply (85-264 V, 47-63 Hz) connects directly to the CPU power terminals — no external 24 V DC power supply required for the CPU itself
  • A 24 V DC source feeds the digital input common terminals; field sensors, limit switches, and proximity devices wire to the 14 DI terminals
  • Relay outputs (DO 0-9, 2 A per contact) connect directly to AC or DC loads such as motor starters, solenoid valves, and indicator lamps
  • Analog input terminals (AI 0-1, 0-10 V) accept voltage signals from transducers or sensors via twisted shielded cable up to 100 m
  • The single PROFINET RJ45 port connects to a managed Ethernet switch, which links to the engineering workstation running STEP 7 V20, HMI panels, variable frequency drives, or distributed PROFINET IO devices

Applications Where the CPU 1214C AC/DC/Relay Earns Its Place

Conveyor and material handling systems are among the most common deployments for this CPU. The combination of 14 digital inputs for position sensors and end-of-travel limits, 10 relay outputs for motor starters and diverters, and 6 high-speed counters for encoder-based position feedback covers a complete single-zone conveyor control loop within one unit.

Bottling and liquid fill lines rely on the 2 analog inputs for fill-level transducer signals and the relay outputs to switch fill pumps and valve solenoids. The integrated PID controller handles closed-loop fill-level regulation without a separate controller module.

HVAC and building mechanical control applications benefit from the AC supply input — most mechanical room panels already run AC distribution — and the relay outputs for direct switching of fans, dampers, and pumps. The -20 to 60 degrees C operating range covers mechanical room and plant floor environments without derating.

High-speed counting applications, such as parts counting on a packaging line or frequency measurement from a flow meter pulse output, use the 6 HSC inputs at up to 100 kHz. This eliminates the need for a dedicated counter module in applications where 6 independent counters are sufficient.

Multi-axis positioning for small pick-and-place machines or material handling gantries is supported up to 8 controlled axes, with 4 pulse-direction axes available when the SB 1222 signal board is installed.

Application Typical Deployment
Conveyor belt speed and position control CPU handles encoder HSC inputs, relay outputs switch motor starters and diverters
Bottling line fill-level monitoring Analog inputs read level transducers; relay outputs switch fill pumps and valves
Multi-axis pick-and-place machine Up to 8 positioning axes managed via integrated motion function blocks
HVAC fan and damper control AC supply feeds CPU directly; relay outputs switch fans, dampers, and pump starters
High-speed parts counting on packaging line 6 HSC inputs at 100 kHz count pulse outputs from optical sensors or encoders
Water treatment pump sequencing Relay outputs sequence pump contactors; PID controller manages pressure or flow setpoints

Specifications an Engineer Needs Before Ordering

Parameter Specification
Supply Voltage AC 85-264 V, 47-63 Hz
Digital Inputs 14 x 24 V DC, parameterizable delay 0.2-12.8 ms
Digital Outputs 10 x relay, 2 A per contact at rated load voltage
Analog Inputs 2 x 0 to +10 V, 625 µs conversion time, input impedance ≥100 kΩ
Analog Outputs None onboard — not available on this variant
High-Speed Counters 6 independent, up to 100 kHz maximum counting frequency
Program and Data Memory 150 KB combined
PROFINET Interface 1 x RJ45, auto-negotiation, auto-crossover, galvanic isolation
Operating Temperature -20 to 60°C horizontal; -20 to 50°C vertical mounting
Physical Dimensions / Weight 110 x 100 x 75 mm / approx. 455 g

Full technical specifications are available on the product page at LeadTime.ca.

6ES7214-1BG40-0XB0 vs. Other CPU 1214C Variants: Which One Do You Actually Need?

Model Supply Digital Outputs Analog Outputs Firmware STEP 7 Minimum
6ES7214-1BG40-0XB0 AC 85-264 V 10 x Relay (2 A) None V4.7 V20 or higher
6ES7214-1BG31-0XB0 AC 85-264 V 10 x Relay (2 A) None V4.5-V4.6 V11 SP2 or higher
6ES7214-1AF40-0XB0 24 V DC 10 x Relay (2 A) None V4.7 V20 or higher
6ES7214-1HG40-0XB0 AC 85-264 V No relay DO Yes V4.7 V20 or higher

If your architecture uses AC mains supply and requires direct relay switching without analog outputs, the 6ES7214-1BG40-0XB0 is the correct choice — check current availability at LeadTime.ca.

Expert Verdict: Honest Assessment and Procurement Reality

The 6ES7214-1BG40-0XB0 is genuinely well-suited for the majority of small-to-medium machine automation tasks where the I/O count fits the onboard capacity. The compact housing at 110 x 100 x 75 mm reduces panel footprint by 40-50% compared to traditional modular PLC racks with separate I/O modules — a measurable advantage in retrofit projects and tight OEM cabinet designs. The relay outputs rated at 2 A per contact with 10 million mechanical cycle durability handle direct AC and DC load switching reliably over years of operation. The 6 high-speed counter inputs at 100 kHz, integrated PID, and 8-axis positioning support make this CPU significantly more capable than the channel count alone suggests. With approximately 500,000+ active STEP 7 programmers worldwide using the SIMATIC S7-1200 platform, finding qualified personnel to program and maintain systems built on this CPU is not a procurement risk.

Where this CPU has real limits: the absence of analog outputs is the most common reason buyers end up on the wrong variant. If any part of your process requires a 4-20 mA or 0-10 V output signal — proportional valve control, VFD speed reference, or setpoint transmission — the 6ES7214-1HG40-0XB0 is the correct selection. The single PROFINET port is also a genuine constraint in distributed architectures where multiple IO devices need direct CPU connection without an external switch; that topology requires a switch in the network design. For applications requiring PROFIsafe or safety-rated I/O, this CPU does not support PROFIsafe and the appropriate path is the S7-1500 family. These are honest limits, not engineering failures — knowing them before ordering saves a return and a project delay.

On the procurement side, the 6ES7214-1BG40-0XB0 is a standard active product with firmware V4.7. Lead times through authorized distributors typically run 2-4 weeks for standard stock orders, with expedited options available at a premium. If your project schedule is tight, confirming stock before committing to a build schedule is worth the 10-minute call. If you are ordering in volume, bundle pricing is available. If this matches your system requirements, view current stock and pricing at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

  • AC power (85-264 V, 47-63 Hz) connects directly to CPU supply terminals — verify polarity and confirm green power LED illuminates before wiring field devices
  • Digital inputs (DI 0-13) require a 24 V DC source at the input common; use shielded cable up to 500 m or unshielded up to 150 m; 6 of the 14 inputs double as HSC inputs for encoder or pulse signals
  • Relay outputs (DO 0-9) can switch AC or DC loads up to 2 A per contact; for inductive loads approaching the 2 A limit, add an external contactor rated ≥10 A driven by the CPU relay output coil
  • Analog inputs (AI 0-1) must use twisted shielded cable with a maximum run of 100 m; ground the shield at the PLC end only and route analog cables separately from digital power lines
  • PROFINET RJ45 connects to a standard Ethernet switch or directly to an engineering workstation; the interface supports auto-negotiation and auto-crossover, but verify the connected switch also supports these features to avoid manual speed negotiation

Compatible Signal Boards and Expansion Modules

The 6ES7214-1BG40-0XB0 supports local expansion through a combination of signal boards, communication modules, and signal modules. The following are documented compatible expansion options referenced in the product brief:

  • SB 1222 Signal Board — Installs directly onto the CPU face; enables pulse-direction positioning for up to 4 additional axes, increasing total axis count when used alongside the integrated 8-axis positioning function
  • Signal Modules (SM) — Up to 8 signal modules can be added for additional digital or analog I/O channels when onboard I/O is insufficient
  • Communication Modules (CM) — Up to 3 communication modules supported for additional serial, AS-Interface, or other protocol connectivity
  • Shared Device Configuration — The PROFINET interface supports connection to a maximum of 2 IO Controllers simultaneously, enabling shared device topologies without additional hardware

What Engineers Get Wrong When Ordering This Part

Before finalizing your purchase order for the 6ES7214-1BG40-0XB0, run through this checklist. Every item below represents a documented ordering or commissioning error that results in returns, project delays, or field failures:

  1. Verify model code on datasheet is 6ES7214-1BG40-0XB0 with exact hyphen and capitalization
  2. Confirm onboard I/O matches application: 14 DI, 10 relay DO, 2 AI only (no DO transistor, no AO)
  3. Check power supply input is AC 85-264 V AC, not DC-only versions (6ES7214-1BG31-0XB0 is older firmware variant)
  4. Ensure PROFINET port is sufficient (single RJ45, no integrated switch)
  5. Verify programming package is STEP 7 V20 or higher available in your engineering environment
  6. Confirm installation altitude does not exceed 5000 m (restrictions apply above 2000 m)
  7. Check relay contact rating: 10 million mechanical cycles, 100,000 at rated voltage (2 A)

If any item on this checklist reveals a mismatch, contact the LeadTime.ca team to identify the correct variant before ordering — we ship worldwide and can confirm availability on alternative SKUs the same day.

Frequently Asked Questions

Does the 6ES7214-1BG40-0XB0 support analog outputs?

No. This variant has 2 analog inputs only — there are no analog outputs onboard. If your application requires analog output channels (0-10 V or 4-20 mA), the correct CPU is the 6ES7214-1HG40-0XB0, which includes analog outputs but does not have relay digital outputs. Do not assume all CPU 1214C variants carry the same I/O configuration.

What is the minimum TIA Portal / STEP 7 version required to program the 6ES7214-1BG40-0XB0?

The 6ES7214-1BG40-0XB0 runs firmware V4.7 and requires STEP 7 V20 or higher (TIA Portal V20+). The older firmware variant 6ES7214-1BG31-0XB0 is compatible with STEP 7 V11 SP2 or higher. If your engineering environment has not been updated to V20, you must either upgrade the software or order the BG31 variant — they are not interchangeable from a firmware management perspective.

How many expansion modules can be connected to this CPU?

The CPU 1214C AC/DC/relay supports up to 8 signal modules for additional I/O, up to 3 communication modules, and 1 signal board that installs directly onto the CPU. This gives a maximum local expansion capacity without needing to move to a distributed PROFINET IO architecture.

What happens to the real-time clock when power is lost?

The integrated hardware real-time clock is backed up for approximately 480 hours — roughly 20 days — without power. After that backup period expires, the clock will lose its time setting. There is no user-replaceable battery; the backup is internal. For applications dependent on accurate timestamping after extended outages, plan for clock resynchronization from a network time source via PROFINET after power restoration.

Can the 6ES7214-1BG40-0XB0 be used in safety (SIL/PL) applications?

No. This CPU does not support PROFIsafe and is not rated for functional safety applications under SIL or PL requirements. Applications requiring safety-rated I/O, safety function blocks, or PROFIsafe communication must use a safety-capable PLC platform such as the SIMATIC S7-1500 series with appropriate safety modules.

What is the relay output durability, and when should maintenance be planned?

Each relay output is rated for 10 million mechanical cycles and 100,000 switching cycles at rated load voltage (2 A). At a switching rate of once per second operating continuously, the at-load cycle limit of 100,000 cycles is reached in approximately 28 hours of continuous operation at rated load. For applications with frequent switching at or near the 2 A rating, plan for preventive maintenance inspection at approximately 80,000 load cycles and log cumulative switching counts in the maintenance record.

Why Order the 6ES7214-1BG40-0XB0 From LeadTime.ca

  • Ships worldwide — no geographic restrictions on quoting or fulfillment
  • Specializes in sourcing industrial automation hardware including hard-to-find or short-lead-time SIMATIC S7-1200 variants
  • Volume pricing available — contact the team for multi-unit orders or project BOM quotes
  • Fast response on availability confirmation — useful when your project schedule depends on a firm ship date before you finalize a build
  • Knowledgeable team familiar with variant differences across the CPU 1214C family — can help confirm you are ordering the correct SKU before the order is placed

At-a-Glance Summary

  • Model: 6ES7214-1BG40-0XB0 — SIMATIC S7-1200, CPU 1214C AC/DC/relay, firmware V4.7
  • Onboard I/O: 14 digital inputs (24 V DC), 10 relay outputs (2 A per contact), 2 analog inputs (0-10 V) — no analog outputs
  • Supply: AC 85-264 V, 47-63 Hz — no separate power supply module required
  • Memory: 150 KB combined program and data; trace memory up to 512 kB
  • High-speed counters: 6 independent inputs, maximum counting frequency 100 kHz
  • Positioning: Up to 8 controlled axes; 4 pulse-direction axes with SB 1222 signal board
  • PROFINET: Single RJ45 port with auto-negotiation, auto-crossover, and galvanic isolation
  • Real-time clock backup: 480 hours (approx. 20 days) without power
  • Operating temperature: -20 to 60°C horizontal; -20 to 50°C vertical
  • Dimensions: 110 x 100 x 75 mm; weight approximately 455 g
  • Relay durability: 10 million mechanical cycles; 100,000 cycles at rated load voltage (2 A)
  • STEP 7 minimum: V20 or higher required for this firmware variant
  • Certifications: ATEX, FM, LR, NK, RoHS, RCM, EMV compliant