SIMATIC S7-200, Digital I/O EM 6ES7223-1BL22-0XA0 6ES7 223-1BL22-0XA0 6ES7223-1BL22-OXAO

6ES7223-1BL22-0XA0 | SIMATIC S7-200 EM 223 Digital I/O — 16 DI + 16 DO / 24VDC / 0.5A per Output / −20 to +60°C / 100×75×30mm 

16 Inputs + 16 Outputs in One Expansion Module

The 6ES7223-1BL22-0XA0 (EM 223) expands a SIMATIC S7-200 CPU's I/O count by adding 16 digital inputs and 16 digital outputs simultaneously. A single EM 223 doubles the I/O capacity of a CPU that starts with 16 or fewer onboard points, bringing the combined system to a density that covers most small to medium machine control requirements.

The EM 223 snaps onto the right side of the S7-200 CPU or the preceding expansion module. The local expansion bus carries power and data between the CPU and all connected expansion modules. No separate power cabling is needed for module communication — the system power at 24V DC supplies the module's field-side circuits as well.

Key Specifications

24VDC Input Tolerance — Operating in Real Supply Conditions

The 24VDC input voltage tolerance of ±20% means the module reliably reads inputs from 21VDC to 28VDC. Industrial 24V supplies are rarely exactly 24V — a supply regulation of ±10% or battery-backed systems with variable charge states can produce voltages across this range. The EM 223's 21–28VDC tolerance ensures that input signals are correctly recognised across the full supply variation range without false readings or missed transitions.

Output channels are fed from the same 24V supply. The 0.5A per channel output current covers solenoid valves (typically 0.1–0.35A), indicator lamps, and small relay coils — the standard actuator load types in machine automation at this I/O density.

Compact Form — 100 × 75 × 30mm

At 100mm high, 75mm wide, and 30mm deep, the EM 223 occupies minimal panel real estate. The S7-200 system's narrow module footprint allows multiple expansion modules to stack in a panel section without the larger chassis footprint of rack-based systems.

For small machine panels — feeders, conveyors, packaging stations — where every millimetre of DIN rail space has a cost, the compact EM 223 form factor keeps the controller system within a manageable enclosure size.

Protection Features — Overcurrent and Overvoltage

The module includes overcurrent and overvoltage protection on the output channels. An output that is shorted or overloaded triggers the protection circuit, cutting the output before damage occurs. The module monitors its own operating condition and reports fault states to the CPU.

For field installations where output wiring can be accidentally shorted during maintenance or equipment movement, the built-in protection prevents repeated module failures from short-circuit events in the field.

Application Scenarios

Conveyor control expansion: An S7-200 CPU manages a conveyor system but needs additional I/O for a new diverter section. One 6ES7223-1BL22-0XA0 adds 16 inputs (limit switches, sensors) and 16 outputs (diverter actuators, indicator lamps) to the existing S7-200 system without replacing the CPU.

Packaging machine: Film drive, sealing, cutting, and reject mechanisms require more I/O than the base S7-200 CPU provides. The EM 223 supplies the additional 32 points needed for the extended machine section.

Legacy S7-200 maintenance: An EM 223 in a running machine fails. The 6ES7223-1BL22-0XA0 direct replacement restores the I/O without programme changes — the CPU continues addressing the same expansion module position after replacement.

FAQ

Q1: What S7-200 CPUs are compatible with the 6ES7223-1BL22-0XA0?

The EM 223 expansion module is compatible with all S7-200 CPUs that support local expansion: CPU 221 (limited), CPU 222, CPU 224, CPU 224XP, and CPU 226. The CPU 221 supports fewer expansion modules than the higher models. Check the specific CPU's maximum expansion module count before planning the system configuration.

Q2: How many EM 223 modules can be connected to one S7-200 CPU?

The number of expansion modules is limited by the CPU type's maximum expansion count. The CPU 226, for example, supports up to 7 expansion modules. Total expansion capacity is also limited by the CPU's available local I/O address space. Each EM 223 occupies two I/O bytes (inputs) and two I/O bytes (outputs) in the CPU's I/O image — plan the I/O address allocation before adding multiple EM 223 modules.

Q3: What programming software is used for the S7-200 system with EM 223?

STEP 7-Micro/WIN is the programming and configuration software for the S7-200 series. The EM 223 is configured in STEP 7-Micro/WIN's system block, where its input and output addresses are assigned. The CPU's built-in programming port connects to the programming PC using a PC/PPI cable. For the S7-200 SMART variant, STEP 7-MicroWIN SMART is the corresponding software.

Q4: What is the maximum output current for the 6ES7223-1BL22-0XA0, and can it drive motor contactors directly?

Each output channel handles up to 0.5A. Small motor contactor coils (for contactors rated up to a few kilowatts) typically draw 0.1–0.3A at 24VDC — within the EM 223's output rating. For larger contactor coils drawing more than 0.5A, an intermediate relay with a 24VDC coil rated within the 0.5A limit is required between the EM 223 output and the contactor coil.

Q5: What replaces the 6ES7223-1BL22-0XA0 for new designs?

The direct replacement part is the 6ES7223-1BL21-0XA0. For new machine designs that currently specify S7-200 I/O, migration to the S7-1200 series with the corresponding SIMATIC S7-1200 expansion modules provides a supported, actively developed platform with a similar I/O footprint.