Siemens 6ES7215-1HG40-0XB0 — CPU 1215C Relay Output Selection Guide

By Abdullah Zahid
12 min read
Siemens 6ES7215-1HG40-0XB0 SIMATIC S7-1200 CPU 1215C DC/DC/Relay compact PLC module for machine automation

Siemens 6ES7215-1HG40-0XB0 SIMATIC S7-1200 CPU 1215C DC/DC/Relay — Specifications, Selection Guide, and Where to Buy

Controls engineers comparing compact PLC CPUs for small-to-mid machine automation are often caught between two questions: does the integrated I/O count cover the application, and is the relay output configuration the right fit for the field devices being driven? The Siemens 6ES7215-1HG40-0XB0 — the SIMATIC S7-1200 CPU 1215C in DC/DC/Relay configuration — answers both directly: 14 digital inputs, 10 relay outputs rated at 2A and 230V AC, 2 analog inputs, and 2 analog outputs, all on-board, in a 130 x 100 x 75 mm DIN-rail module. It runs on 20.4–28.8V DC input, ships with two PROFINET ports, and carries 125 KB of program and data memory — enough to handle most mid-range machine control programs without expanding to the S7-1500 line.

If you have already confirmed this is the correct variant for your system, check current pricing and availability for the 6ES7215-1HG40-0XB0 at LeadTime.ca — ships worldwide.

Who Should Buy the 6ES7215-1HG40-0XB0 — and Who Should Not

This CPU is the right purchase when your application fits squarely within the integrated I/O envelope and your output loads are 230V AC motors, solenoids, or heating elements that relay contacts can switch reliably at 2A.

  • Application requires no more than 14 digital inputs, 10 relay digital outputs, 2 analog inputs, and 2 analog outputs without external signal modules
  • Output loads are 230V AC devices — motor starters, solenoids, heating elements — that relay contacts are appropriate for at up to 2A per output
  • System supply delivers 20.4–28.8V DC; an external 5A DC upstream breaker is included in the panel design
  • Cabinet has at least 130 mm width and 75 mm depth available for DIN-rail mounting
  • PROFINET is already deployed or planned in the facility; two on-board Gigabit ports eliminate the need for a separate communication module
  • Operating environment stays within -20 to +60°C horizontal mounting or -20 to +50°C vertical mounting

If your outputs need 24V DC transistor switching — faster than 10 ms mechanical relay switching — the 6ES7215-1AG40-0XB0 (DC/DC/DC variant with 0.5A per output) is the correct alternative. If your I/O count is smaller and cabinet space is the primary constraint, the 6ES7214-1HG40-0XB0 at 70 mm width with 16 I/O points and 50 KB memory is worth reviewing first.

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What the 6ES7215-1HG40-0XB0 Actually Does in a Live System

The 6ES7215-1HG40-0XB0 is the central processor in a SIMATIC S7-1200 control system — the part that executes the logic program, manages I/O, runs PID loops, handles high-speed counting at up to 100 kHz across 6 channels, and communicates upstream to SCADA or PROFINET distributed I/O over two built-in Gigabit Ethernet ports. It is not a gateway, not a remote I/O head, and not a safety CPU. It is a standalone programmable controller with enough on-board I/O to run a complete small machine without any additional signal modules — a meaningful distinction when cabinet space and BOM complexity are constrained.

The DC/DC/Relay designation tells the full power story: the unit accepts 24V DC input, provides a 24V DC output for field device power, and switches loads through relay contacts rather than transistor outputs. That means the relay outputs can directly control 230V AC motor starters or solenoids rated up to 2A — eliminating an external relay tier in many small machine designs. The tradeoff is switching speed: at approximately 10 ms per relay contact, these outputs are not suitable for PWM, pulse-direction motor control output, or high-frequency cycling applications. For those, the 1AG40 DC output variant is the right selection.

The 125 KB program and data memory, combined with a real-time clock backed up for 480 hours and a built-in PID controller, positions this CPU for applications that need time-based scheduling, closed-loop process control, and multi-axis positioning simultaneously — without the cost or footprint of the S7-1500 platform.

Typical System Architecture for the CPU 1215C

The 6ES7215-1HG40-0XB0 sits at the top of the field-level control chain — receiving its program from TIA Portal over PROFINET, executing logic locally, and pushing outputs directly to field devices or downstream distributed I/O nodes.

  • Engineering workstation running STEP 7 V20 or TIA Portal V15+ connects via PROFINET Port 1 for programming and diagnostics
  • CPU 1215C executes the logic program, manages all 28 on-board I/O points, runs PID loops, and tracks real-time clock events
  • PROFINET Port 2 daisy-chains to ET 200SP remote I/O heads or HMI panels if distributed I/O is required beyond the on-board 28 points
  • Relay outputs wire directly to motor starter coils, solenoid valves, and 230V AC control loads in the field panel
  • 24V DC analog inputs receive signals from pressure transmitters, temperature sensors, or level transducers via shielded twisted-pair cable up to 100 m

Where Engineers Actually Deploy This CPU

Packaging machine builders are among the most consistent users of this variant. The 14 digital inputs accommodate the typical array of limit switches, proximity sensors, and photoeyes on a labeling or filling line, while the 10 relay outputs drive motor starters and reject solenoids without intermediate relay modules. The 100 kHz high-speed counter inputs — 6 channels available — handle encoder feedback or product counting at line speed.

Conveyor system automation is another natural fit. Progressive motor start and stop sequences across belt sections use relay outputs directly, the 0–20 mA analog output connects to a VFD for speed ramp control, and PROFINET carries belt-load status data upstream to the facility monitoring system over the second built-in port.

In building HVAC and facility control applications, the real-time clock with 480-hour battery backup handles time-of-day scheduling for multi-stage heating and cooling relay sequences, while the 2 analog inputs handle temperature sensor signals. The compact 130 mm width fits in standard electrical panels alongside other control gear.

Process batch mixing applications use the built-in PID controller to manage pump speed through the 0–20 mA analog output, with 2 analog inputs monitoring level and temperature simultaneously. The 14 digital inputs cover alarm contacts, emergency stops, and valve position feedback without any additional modules.

Application Typical Deployment
Packaging and labeling machines 14 DI for sensors, 10 relay DO for motor starters and solenoids, HSC for product counting
Conveyor system automation Relay outputs for section motors, 0–20 mA AO to VFD, PROFINET to facility SCADA
Building HVAC control Analog inputs for temperature sensing, relay outputs for multi-stage heating/cooling, RTC for scheduling
Process batch mixing PID loop via AO to pump VFD, analog inputs for level/temp, DI for alarms and E-stop
Motor control panels Progressive start/stop relay sequences, thermal overload logic, PROFINET upstream reporting
Remote site distributed control CPU 1215C as gateway with PROFINET Port 2 to local I/O, Port 1 back to central facility network

Purchase-Decision Specifications for the 6ES7215-1HG40-0XB0

Specification Value
Power Supply Input 20.4–28.8V DC; 30W typical
Digital Inputs 14 @ 24V DC; 6 channels usable for HSC at 100 kHz max
Digital Outputs 10 relay contacts @ 2A, 230V AC max; approx. 10 ms switching
Analog Inputs 2 @ 0–10V DC; 10-bit resolution; 100 kΩ input impedance
Analog Outputs 2 @ 0–20 mA DC sink type
Program / Data Memory 125 KB
PROFINET Ports 2 Gigabit; daisy-chain or star topology
Real-Time Clock 480-hour battery backup; ±60 s/month drift at 25°C
Operating Temperature -20 to +60°C horizontal; -20 to +50°C vertical
Dimensions / Weight 130 x 100 x 75 mm; 585 g

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

CPU 1215C vs. 1214C vs. 1AG40 vs. 1215R — Which One Do You Actually Need?

Model Output Type Memory I/O Points DIN Width Relay Output Price Tier Best For
6ES7215-1HG40-0XB0 Relay 2A / 230V AC 125 KB 28 130 mm Yes Mid Small machines, direct 230V AC load switching
6ES7215-1AG40-0XB0 24V DC, 0.5A 125 KB 28 130 mm No Mid-High Fast switching, PWM, modular I/O expansion
6ES7214-1HG40-0XB0 Relay 2A 50 KB 16 70 mm Yes Low Micro applications, tight cabinet, budget-constrained
6ES7215-1SR50-0XB0 Relay 2A 125 KB 28 260 mm Yes High Redundant dual-CPU failover, high-availability systems
S7-1500 (1511F-1PN) DC or relay (modular) 500 KB+ Modular 150 mm Optional High Advanced safety, motion control, large logic programs

If your application needs 230V AC relay switching with 28 on-board I/O points and 125 KB memory, the 6ES7215-1HG40-0XB0 is the correct selection — check current stock and availability at LeadTime.ca.

Expert Verdict: Honest Assessment for Engineers and Procurement Teams

The 6ES7215-1HG40-0XB0 earns its place as a go-to CPU for small-to-mid machine automation when the output loads are 230V AC devices that relay contacts can drive directly. The combination of 14 DI, 10 relay DO, 2 AI, and 2 AO in a 130 mm wide module — with two PROFINET Gigabit ports and a built-in PID controller included — genuinely reduces BOM complexity for the majority of standalone machine builds. The 480-hour real-time clock backup and 6-channel 100 kHz high-speed counter capability add value that justifies the price point over entry-level alternatives. For packaging, conveyor, HVAC, and batch process applications operating within the I/O envelope, this CPU delivers without requiring signal module expansion.

The real limits are predictable and worth stating plainly. At 125 KB of program and data memory, complex multi-recipe batch programs or applications with large data logging requirements will hit the ceiling — the S7-1500 platform is the appropriate upgrade path in those cases. The relay outputs switch at approximately 10 ms, which eliminates this CPU from any application requiring fast digital output cycling, PWM motor control, or high-frequency pulse output — select the 6ES7215-1AG40-0XB0 instead. And at 60°C ambient in vertical mounting, simultaneous relay output loading is thermally constrained — a factor that is easy to miss during cabinet design. Plan the thermal budget before ordering, not after.

On the procurement side, the 6ES7215-1HG40-0XB0 is an actively stocked part at distributors globally, with standard lead times in the 2–4 week range under normal conditions. Volume orders of 10 or more units typically qualify for framework pricing. Counterfeits exist in the secondary market for this family — always confirm you are purchasing a genuine manufacturer part through an authorized source. 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

  • Power input: Connect 24V DC within the 20.4–28.8V range to the +24V and GND terminals; install an external 5A DC circuit breaker upstream — the unit has no internal overcurrent protection
  • Digital inputs: 14 channels operate at 24V DC nominal; signal threshold is ≥15V DC for logic 1 and ≤5V DC for logic 0; source or sink configuration is selectable
  • Relay outputs: 10 NO relay contacts rated 2A at 230V AC maximum; connect load between the relay common and NO terminal; install surge suppression (varistor or TVS diode) on inductive loads to protect contacts
  • Analog I/O: 2 analog inputs accept 0–10V DC at ≥100 kΩ input impedance over shielded twisted-pair cable up to 100 m; 2 analog outputs source 0–20 mA DC sink type — connect load between the AO terminal and 24V return
  • PROFINET: Connect Category 5e or higher twisted-pair cable to either RJ45 port; maximum segment length is 100 m; daisy-chain or star topology both supported per IEC 61158

Signal Module and Communication Expansion Options

The 6ES7215-1HG40-0XB0 supports system expansion beyond its 28 on-board I/O points through the SIMATIC S7-1200 modular architecture. The following expansion options are supported:

  • Up to 8 signal modules can be added to the right side of the CPU for additional digital or analog I/O channels
  • Up to 3 communication modules can be installed to the left side for additional serial, fieldbus, or industrial Ethernet protocols
  • 1 signal board can be inserted into the CPU front face for additional I/O without consuming DIN-rail space — compatible with the SB 1222 for additional pulse-direction axis output
  • PROFINET Port 2 supports daisy-chained ET 200SP remote I/O heads for distributed field-level expansion beyond the local panel
  • Firmware V4.7 enables OPC UA communication for direct integration with MES and SCADA platforms without an additional gateway module

Wrong-Part Prevention Checklist Before You Order

Before placing an order for the 6ES7215-1HG40-0XB0, verify each of the following against your application requirements — a single mismatch on any item can result in a costly re-order or project delay:

  1. Verify output type: This model has relay outputs (2A max). If application needs 24V DC sinking/sourcing, select 1AG40 variant instead.
  2. Check power supply voltage: Unit requires 20.4-28.8V DC input. Confirm power supply delivers DC, not AC.
  3. Count on-board I/O: 14 DI, 10 DO relay, 2 AI, 2 AO total. Confirm this meets minimum I/O needs (cannot expand beyond 3 communication modules).
  4. Confirm PROFINET usage: Two PROFINET ports are built-in. If Ethernet communication is not needed, consider lower-cost models.
  5. Verify operating environment: Max 60°C horizontal or 50°C vertical. Confirm thermal environment is within range.
  6. Check program memory sufficiency: 125 KB program/data memory. Estimate logic size; complex applications may require S7-1500 line.
  7. Confirm placement mount method: Standard DIN rail. Verify cabinet has adequate space (130 mm width required).

If every item on this list checks out, proceed to the 6ES7215-1HG40-0XB0 product page at LeadTime.ca to confirm current stock and request a quote — or contact the team directly if you need sourcing confirmation before finalizing your BOM.

Frequently Asked Questions

Can I add more I/O modules to the 6ES7215-1HG40-0XB0 after initial installation?

Yes. The CPU supports up to 8 signal modules for additional digital or analog I/O, up to 3 communication modules for additional protocol interfaces, and 1 signal board that installs directly into the CPU face. Expansion modules connect via the S7-1200 local bus on the right side of the CPU and are configured through TIA Portal V15 or higher.

What is the practical difference between the 6ES7215-1HG40-0XB0 relay outputs and the 1AG40 DC outputs?

The relay outputs on the 6ES7215-1HG40-0XB0 switch at approximately 10 ms, are rated at 2A per contact at 230V AC maximum, and use mechanical NO relay contacts — well-suited for infrequent switching of motor starters, solenoid valves, and heating elements. The 1AG40 DC outputs switch in under 1 ms, are rated at 0.5A at 24V DC, support PWM, and are appropriate for fast digital cycling, solid-state drive control, and high-frequency pulse output applications.

What happens if my operating temperature exceeds the rated limits for the CPU?

The 6ES7215-1HG40-0XB0 is rated for -20 to +60°C in horizontal mounting and -20 to +50°C in vertical mounting. Simultaneous relay output loading is also thermally constrained at elevated ambient temperatures — at 60°C in vertical mounting, fewer than the full 10 outputs can be simultaneously energized. Always confirm your cabinet thermal environment and mounting orientation against these limits before installation.

Is the 6ES7215-1HG40-0XB0 suitable for safety-critical emergency stop functions?

No. The relay contacts on this CPU are not rated or certified for SIL (Safety Integrity Level) critical functions. Emergency stop circuits require certified safety relay modules or a safety-rated CPU with appropriate SIL certification. For safety applications, review the SIMATIC S7-1500 safety CPU range or dedicated safety relay modules.

Can I upgrade the firmware on the 6ES7215-1HG40-0XB0 in the field?

Yes. Firmware V4.5 and V4.7 are both available and can be loaded via Ethernet download through TIA Portal or via memory card. Firmware rollback is not supported, so always validate a new firmware version in a lab or non-production environment before updating live plant CPUs.

How do I confirm I am purchasing a genuine 6ES7215-1HG40-0XB0 and not a counterfeit?

Purchase only through authorized distributors who can provide documentation confirming the part originates from the manufacturer. Counterfeit S7-1200 modules have been identified in secondary markets. Request a certificate of authenticity or a distributor authorization confirmation with your order — LeadTime.ca sources through verified supply channels and can provide this documentation on request.

Why Source the 6ES7215-1HG40-0XB0 Through LeadTime.ca

  • Ships worldwide — no geographic restrictions on orders; available to engineers and procurement teams on every continent
  • Specializes in sourcing industrial automation hardware including hard-to-find and time-sensitive SIMATIC S7-1200 variants
  • Volume pricing available for orders of 10 or more units — contact the team to discuss framework agreements
  • Fast response on lead time confirmation before you commit to a build schedule
  • Genuine manufacturer parts with sourcing documentation available on request

At-a-Glance Summary

  • Model: Siemens 6ES7215-1HG40-0XB0 — SIMATIC S7-1200 CPU 1215C, DC/DC/Relay configuration
  • On-board I/O: 14 digital inputs at 24V DC, 10 relay outputs at 2A / 230V AC max, 2 analog inputs at 0–10V DC, 2 analog outputs at 0–20 mA DC
  • Program and data memory: 125 KB; real-time clock with 480-hour battery backup
  • High-speed counter channels: 6 at 100 kHz maximum frequency measurement
  • PROFINET connectivity: 2 Gigabit ports built-in; supports daisy-chain and star topology
  • Power supply input: 20.4–28.8V DC; 30W typical consumption; external 5A upstream breaker required
  • Operating temperature: -20 to +60°C horizontal; -20 to +50°C vertical; humidity ≤95% RH non-condensing
  • Dimensions: 130 x 100 x 75 mm; weight 585 g; standard DIN-rail mounting
  • Programming environment: STEP 7 V20 or TIA Portal V15 and above; firmware V4.7 with OPC UA support
  • Certifications: CE mark, RoHS compliant; eClass 27-24-22-07
  • Primary alternates: 6ES7215-1AG40-0XB0 for DC transistor outputs; 6ES7214-1HG40-0XB0 for smaller I/O footprint; 6ES7215-1SR50-0XB0 for redundancy