Siemens es7223-1ph32-0xb0

By Abdullah Zahid
13 min read
Siemens 6ES7223-1PH32-0XB0 SM 1223 digital I/O signal module for SIMATIC S7-1200 PLC machine control

Siemens 6ES7223-1PH32-0XB0: SIMATIC S7-1200 Digital I/O SM 1223, 8 DI/8 DO Relay Module — Complete Specs, Variants, and Selection Guide

Controls engineers expanding an S7-1200 system to handle more sensor inputs and actuator outputs typically arrive at one of two decisions: source the exact catalog number that matches what is already validated in their system, or verify they are not ordering an output-only SM 1222 by mistake. The Siemens 6ES7223-1PH32-0XB0 is the SIMATIC S7-1200 Digital I/O SM 1223 — a compact signal module providing 8 channels of 24V DC digital input and 8 relay outputs rated at 2A per channel, housed in a 45 × 100 × 75mm footprint that mounts directly on the S7-1200 rail via the front connector slot. It has been in active delivery since March 2013 and remains a current-production part.

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

Who Should Buy the 6ES7223-1PH32-0XB0 — and Who Shouldn't

This module is the correct choice for engineers expanding I/O on a SIMATIC S7-1200 base unit where mixed digital inputs and relay outputs are required in a single slot. Confirm all of the following before ordering:

  • Your host controller is a SIMATIC S7-1200 series PLC with an unoccupied front connector slot compatible with the SM 1223 module type
  • Field instrumentation operates at 24V DC — this module accepts 24V DC sink/source inputs only; 110V or 230V AC input signals require external conversion
  • Connected output loads do not exceed 2A per relay channel and 10A aggregate per output group
  • The installation environment remains within -20 to +60°C operating range for the standard version
  • Cabinet space accommodates the 45 × 100 × 75mm module footprint

If your environment exceeds +60°C or requires conformal coating for washdown or outdoor cabinets, this is not the correct variant — order the SIPLUS 6AG1223-1PH32-2XB0 instead, which covers -40 to +70°C with MIL-grade conformal coating. If you need relay outputs only, the SM 1222 is the leaner option; if inputs only, look at the SM 1221.

On this page:

What the SM 1223 Actually Does in a Running System

The Siemens 6ES7223-1PH32-0XB0 is classified as a Digital Input/Output Signal Module within the SIMATIC S7-1200 Automation System family. Its role is straightforward: it receives discrete 24V DC signals from field devices — proximity switches, limit switches, pressure switches, door contacts — processes them through the connected S7-1200 CPU, and closes or opens eight independent relay contacts to command external equipment. Those relay contacts switch loads from 5V DC up to 250V AC, covering solenoid valves, motor starter coils, indicator lights, and small contactors within the 2A per channel rating.

What separates this module from a passive terminal block is its integrated diagnostic layer. Each input and output channel has a status LED visible from the cabinet door. The module monitors its own 24V DC supply voltage and generates alarm messages to the CPU if that supply falls out of specification. A maintenance indicator LED flags faults without requiring TIA Portal to be open. The result is that technicians can diagnose the majority of wiring and supply faults by reading the module face before touching a laptop. This diagnostic depth has made the SM 1223 a default choice on machines where downtime cost justifies the premium over a bare relay terminal block.

The module's relay outputs are rated for 10 million mechanical switching cycles and 100,000 electrical cycles at rated load — figures that are meaningful in high-frequency cycling applications like packaging or sorting lines where output duty cycles are demanding. Output switching delay is 10ms maximum in both directions, which is acceptable for most discrete machine control tasks but should be verified against any time-critical interlock requirements in the application.

Where the 6ES7223-1PH32-0XB0 Sits in Your Signal Chain

The SM 1223 sits one step downstream of the S7-1200 CPU in the I/O signal chain, acting as the physical interface between the PLC's logic and field devices on both the input and output sides simultaneously.

  • S7-1200 CPU base unit — executes the control program and communicates with attached signal modules via the internal bus through the front connector
  • 6ES7223-1PH32-0XB0 — receives 24V DC sensor signals on 8 input channels and drives 8 independent relay contacts toward field loads
  • Input side field devices — proximity switches, limit switches, pressure switches, door interlocks wired to DI terminals with cable runs up to 500m shielded or 300m unshielded
  • Output side field loads — solenoid valve coils, motor starter coils, indicator lamps, small contactors wired to relay output terminals with cable runs up to 500m shielded or 150m unshielded
  • External 24V DC power supply — feeds the module directly; the module has no integrated power supply or circuit breaker, so an external fused disconnect is mandatory in the supply line

Industries and Applications That Depend on This Module

In discrete manufacturing — automotive assembly, CNC machining, metalworking — the SM 1223 is routinely used to monitor limit switches and spindle status on one side while controlling solenoid valves, coolant pumps, and chip conveyor motors on the other. The relay output's ability to switch both DC coils and AC lamp loads without additional isolation hardware is what makes it efficient in these mixed-voltage environments.

Filling and packaging lines rely on this module's input channels to read fill-level sensors, cap presence detectors, and pressure switches simultaneously, while relay outputs drive fill solenoids, capping motors, and reject gates in coordinated sequences. The 2A relay rating covers the coil loads of the majority of pneumatic solenoid valves used in food and beverage and pharmaceutical packaging without requiring intermediate relay stages.

Conveyor and material handling systems benefit from the module's scalability — multiple SM 1223 units can be chained on a single S7-1200 to cover long transfer lines where position sensors and diverter solenoids are distributed across workstations. Environmental monitoring panels use the 8 DI channels for door switches, temperature alarms, and humidity sensors, while relay outputs command cooling fans, dehumidifiers, and warning horns.

Application Typical Deployment
CNC and machine tool control Limit switch inputs, spindle status; relay outputs to solenoid valves and coolant pumps
Filling and bottling lines Level sensor inputs, cap detect; relay outputs to fill solenoids and reject gates
Conveyor and sorting systems Product position and jam sensor inputs; relay outputs to motor starters and diverter solenoids
Packaging and labeling machines Label sensor and tension detect inputs; relay outputs to labeler drive and reject arm
Environmental and cabinet monitoring Door switch and temperature alarm inputs; relay outputs to cooling fans and alarm horns
Pharmaceutical production Pressure switch and flow sensor inputs; relay outputs to isolation valves and status indicators

Purchase-Decision Specs: What Engineers Actually Need to Confirm

Specification Value
Digital inputs 8 channels, 24V DC, sink/source configurable
Digital outputs 8 channels, relay type, 2A per channel
Output aggregate current per group 10A maximum (horizontal mounting at 50°C)
Output voltage range 5–30V DC or 5–250V AC
Output lamp load capacity 30W DC / 200W AC
Relay mechanical life 10 million cycles; 100,000 cycles at rated load
Max input cable length 500m shielded / 300m unshielded
Operating temperature (standard) -20 to +60°C
Dimensions (W × H × D) 45 × 100 × 75mm
Weight 230g

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

6ES7223-1PH32-0XB0 vs. SM 1222, SM 1221, and SIPLUS: Which Variant Do You Need?

Product Catalog Number DI Count DO Count Output Type Operating Temp Best For
SM 1223 (standard) 6ES7223-1PH32-0XB0 8 8 Relay, 2A -20 to +60°C Mixed sensor/actuator control in climate-controlled cabinets
SIPLUS SM 1223 6AG1223-1PH32-2XB0 8 8 Relay, 2A -40 to +70°C Outdoor cabinets, washdown, extreme thermal cycling
SM 1222 (output only) SM 1222 series 0 8 Relay -20 to +60°C Actuator-only expansion with no additional sensor monitoring needed
SM 1221 (input only) SM 1221 series 8 0 N/A -20 to +60°C Sensor-only monitoring with no output control required
SM 1226 (compact mixed) SM 1226 series 4 4 Relay -20 to +60°C Lower I/O count applications where full 8/8 is excess

For the majority of S7-1200 machine builds requiring both sensor monitoring and actuator control, the 6ES7223-1PH32-0XB0 is the correct choice — check current availability at LeadTime.ca.

Expert Verdict: Honest Assessment for Controls Engineers

The Siemens 6ES7223-1PH32-0XB0 earns its place as the default I/O expansion module on S7-1200 builds not because it is the only option, but because it removes the most common engineering decisions from the table. The relay outputs handle AC and DC loads from 5V to 250V AC without additional isolation hardware. The integrated supply monitoring and per-channel status LEDs reduce commissioning time and make field troubleshooting faster. The 45 × 100 × 75mm footprint is predictable for cabinet layout. For controls engineers working in discrete manufacturing, food and beverage, packaging, or conveyor systems — and operating in standard industrial environments within -20 to +60°C — this module is simply the right tool for the job.

The honest limits are equally clear. The 2A per channel relay rating is not sufficient to drive motor starter coils directly in many applications — an external intermediate relay is required for loads exceeding 2A, which adds a wiring step that engineers sometimes underestimate at project planning. The standard version's -20 to +60°C ceiling rules it out for outdoor enclosures or installations adjacent to furnaces without upgraded ventilation. And because the S7-1200 platform itself has a maximum of three plugged signal modules per base unit, engineers who need more than 24 DI and 24 DO should validate their expansion architecture before ordering a stack of SM 1223 units and discovering the platform ceiling mid-build.

On the procurement side, the SM 1223 is a mature, actively produced part with stable availability — typical lead time in most markets is 1 to 4 weeks. The SIPLUS 6AG1223-1PH32-2XB0 extended-temperature variant tends to carry a 30–40% price premium and longer lead times of 4 to 8 weeks in normal conditions. If a project timeline is firm, ordering the SIPLUS variant early is advisable rather than treating it as a drop-in swap at the last moment. 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: Key Requirements Before You Start

  • The module mounts directly on the S7-1200 base unit front connector slot — power down the CPU before insertion; the latch must click positively to confirm full electrical and mechanical engagement
  • A 24V DC external supply with a fused disconnect is mandatory; the SM 1223 has no internal circuit breaker, and an unprotected short circuit will damage the module
  • Input cable runs beyond 50m should use shielded twisted-pair with the shield grounded at the PLC end only — maximum cable length is 500m shielded or 300m unshielded for inputs, 500m shielded or 150m unshielded for outputs
  • Relay output contacts are rated 2A per channel with 10A aggregate per group at horizontal mounting up to 50°C — verify load current before wiring; inductive AC loads exceeding the rating require an external varistor or RC snubber to suppress contact arcing
  • After physical installation, the module is auto-detected in TIA Portal hardware configuration — create 8 Boolean input and 8 Boolean output variables, then verify each channel by toggling output bits and confirming relay clicks and status LED illumination before closing the cabinet

Compatible Modules and S7-1200 System Expansion

The 6ES7223-1PH32-0XB0 operates within the SIMATIC S7-1200 Automation System ecosystem. The following module types are compatible and commonly deployed alongside it in expanded S7-1200 control architectures:

  • SM 1221 (8 DI only) — adds pure digital input capacity when no additional relay outputs are needed at that expansion slot
  • SM 1222 (8 DO relay only) — adds pure digital output capacity where all sensor inputs are already handled
  • SM 1226 (4 DI / 4 DO) — compact mixed I/O option when full 8/8 count is not required
  • SIPLUS 6AG1223-1PH32-2XB0 — pin-compatible extended temperature and conformal coating variant; no PLC program changes required when swapping from the standard module

Note that the S7-1200 base unit supports a maximum of three plugged signal modules — confirm total module count in your hardware configuration before ordering additional SM 1223 units to avoid exceeding the platform expansion limit.

Wrong-Part Prevention: Verify Before You Order

Use this checklist before placing a purchase order to avoid receiving the wrong module or creating a mismatch that causes project delay:

  1. Verify host PLC is SIMATIC S7-1200 series, not S7-1500 or legacy S7-300 (different mounting and protocols)
  2. Confirm available front connector slot on the S7-1200 base unit is unoccupied and matches SM 1223 connector type
  3. Check field sensor voltage is 24V DC; do NOT use with 110V or 230V AC inputs without external converter
  4. Verify relay output load does not exceed 2A per channel or 10A aggregate per group to prevent module damage
  5. Ensure operating environment temperature falls within -20 to +60°C for standard version or -40 to +70°C for SIPLUS; confirm no condensation during storage/startup
  6. Confirm external protection (fuses, surge suppressors) is provided on DC supply and output circuits as module has no integrated circuit breaker
  7. Check cable lengths: maximum 500m shielded (inputs), 300m unshielded (inputs); 500m shielded, 150m unshielded (outputs) to avoid signal degradation

If any item on this checklist raises a flag, contact the LeadTime.ca team before ordering — our technical team can help confirm the correct catalog number for your application.

Frequently Asked Questions

How many SM 1223 modules can be connected to a single S7-1200 base unit?

The S7-1200 base unit supports a maximum of three plugged signal modules. If you need more than three SM 1223 units — or any combination of three signal modules — you will need to evaluate distributed I/O architecture rather than continuing to stack modules on the same base unit. Confirm your exact base unit model's expansion limit in the S7-1200 hardware documentation before designing a multi-module layout.

Can the SM 1223 relay outputs switch 230V AC loads directly?

The relay output voltage range includes 5–250V AC, so the contacts are rated for AC voltages in that range. However, the 2A per channel current limit and the 200W AC lamp load rating must not be exceeded. For inductive AC loads — motor starter coils, solenoid valves — verify that inrush current and steady-state current both remain within the 2A rating; if not, use the SM 1223 relay output to trigger an external intermediate contactor rated for the full load.

Does the SIPLUS 6AG1223-1PH32-2XB0 require any PLC program changes compared to the standard module?

No. The SIPLUS 6AG1223-1PH32-2XB0 is pin-compatible and firmware-compatible with the standard 6ES7223-1PH32-0XB0. Swapping one for the other requires no changes to TIA Portal hardware configuration or PLC program variables. The only differences are the extended operating temperature range (-40 to +70°C) and the MIL-I-46058C conformal coating on the SIPLUS variant.

What does the diagnostic alarm LED indicate, and how should it be handled?

The diagnostic alarm LED on the SM 1223 indicates a supply voltage fault, input group fault, or internal module error. The first diagnostic step is to measure the 24V DC supply at the module connector — it must fall within 24V ±20% per Siemens specification. A power cycle of the S7-1200 will clear temporary faults. If the alarm persists after confirming supply voltage and power cycling, review the diagnostic messages in TIA Portal and consider replacing the module if the fault cannot be resolved through software.

What is the maximum cable length for SM 1223 input wiring, and when is shielding required?

The maximum input cable length is 500m for shielded cable and 300m for unshielded cable. Shielded twisted-pair cable is recommended for all runs in environments with significant EMI — particularly runs over 30m that are routed near power cables or variable frequency drives. The shield should be grounded at the PLC end only to avoid ground loops. For output wiring, the limits are 500m shielded and 150m unshielded.

Is the 6ES7223-1PH32-0XB0 still in production, and what is a realistic lead time?

Yes — the 6ES7223-1PH32-0XB0 carries Active Product status with delivery release confirmed since March 2013. In typical market conditions, lead time from authorized distributors is 1 to 4 weeks. During supply chain disruptions this can extend to 12 or more weeks. Ordering one or two spare units for inventory is a low-risk strategy given the module's low obsolescence probability as a current-production part.

Why Source Through LeadTime.ca

  • LeadTime.ca ships the Siemens 6ES7223-1PH32-0XB0 worldwide — no regional sourcing restrictions
  • Real-time stock visibility and lead time confirmation before you commit to a build schedule
  • Volume pricing available for multi-unit orders — contact the team directly for project quotes
  • Technical team available to confirm correct catalog number and variant selection before order placement
  • Sourcing support for hard-to-find variants including the SIPLUS 6AG1223-1PH32-2XB0 extended-temperature version

At-a-Glance Summary

  • Catalog number: Siemens 6ES7223-1PH32-0XB0 — SIMATIC S7-1200 Digital I/O SM 1223, 8 DI/8 DO
  • 8 digital inputs at 24V DC, sink/source configurable; 8 relay outputs at 2A per channel, 10A aggregate per group
  • Relay contacts switch 5–30V DC or 5–250V AC; 30W DC lamp load, 200W AC lamp load
  • Relay mechanical life: 10 million cycles; electrical life at rated load: 100,000 cycles
  • Module dimensions: 45 × 100 × 75mm; weight: 230g; IP20 housing
  • Standard operating temperature: -20 to +60°C; extended temperature SIPLUS variant (6AG1223-1PH32-2XB0): -40 to +70°C
  • Maximum input cable: 500m shielded / 300m unshielded; output cable: 500m shielded / 150m unshielded
  • Active product status since delivery release March 2013; typical lead time 1–4 weeks in normal supply conditions
  • Requires external 24V DC supply with fused disconnect — no integrated circuit breaker
  • S7-1200 base unit maximum: 3 plugged signal modules total — verify slot availability before ordering