6ES7216-2AD23-0XB0 SIMATIC S7-200
The Siemens SIMATIC S7-200 CPU 226 (part number 6ES7216-2AD23-0XB0) is a compact programmable logic controller belonging to the S7-200 micro-PLC family. This unit is a DC-powered variant featuring 24 digital inputs and 16 digital outputs, designed for small to medium-scale automation tasks. It is part of Siemens' established S7-200 series, which is widely deployed in standalone machine control and simple process automation.
The CPU 226 offers an instruction execution time of 0.22 µs per Boolean instruction and supports up to 8 KB of program memory and 5 KB of data memory. It provides two RS-485 communication ports (Port 0 and Port 1) supporting PPI, MPI, and Freeport protocols, enabling flexible integration with HMI panels, programming devices, and third-party equipment. The unit supports high-speed counters (up to 30 kHz), pulse outputs, and interrupt-driven I/O, and can be expanded with up to 7 expansion modules for additional I/O or special functions. A real-time clock is integrated for time-stamped data logging and scheduled control tasks.
The SIMATIC S7-200 CPU 226 is commonly used in packaging machinery, conveyor systems, material handling equipment, and small-scale process control applications. Its compact DIN-rail mountable form factor and broad expansion capability make it suitable for OEM machine builders requiring a cost-effective yet capable controller. Industries such as food and beverage, automotive assembly, and building automation frequently deploy this CPU for localized machine control.
Technical Specifications
| Digital Inputs | 24 |
|---|---|
| Digital Outputs | 16 (DC transistor) |
| Input Voltage | 24 V DC |
| Output Voltage | 24 V DC |
| Program Memory | 8 KB |
| Data Memory | 5 KB |
| Boolean Execution Time | 0.22 µs per instruction |
| Communication Ports | 2 x RS-485 (Port 0 and Port 1) |
| Supported Protocols | PPI, MPI, Freeport |
| High-Speed Counters | 6 (up to 30 kHz) |
| Pulse Outputs | 2 (up to 20 kHz) |
| Maximum Expansion Modules | 7 |
| Real-Time Clock | Integrated |
| Operating Temperature | 0 °C to +55 °C |
| Storage Temperature | -40 °C to +70 °C |
| Relative Humidity | 5% to 95% (non-condensing) |
| Mounting | DIN rail or panel mounting |
| Certifications | CE, UL, cUL, FM |
Common Fault Codes
- Fault Code 1
- Non-fatal runtime error: Illegal instruction encountered during program execution.
Review and correct the user program in STEP 7 Micro/WIN. Check for corrupted program blocks and re-download the program. - Fault Code 2
- Non-fatal runtime error: Indirect address out of range.
Inspect the user program for pointer-based addressing errors. Correct the indirect address references and re-download the program. - Fault Code 3
- Non-fatal runtime error: Divide by zero detected in math operation.
Add input validation logic in the program to prevent division by zero before the math instruction executes. - Fault Code 4
- Fatal runtime error: User program watchdog timeout. CPU has stopped execution.
Check for infinite loops or excessively long scan cycles in the user program. Optimize program logic and ensure the watchdog timer setting is appropriate. - Fault Code 5
- Fatal runtime error: Memory error detected in program or data memory.
Perform a CPU memory clear (MRES) and re-download the program. If the fault persists, the CPU module may require replacement. - Fault Code 6
- I/O bus error: Communication failure detected on the expansion I/O bus.
Check wiring and connectors between the CPU and expansion modules. Verify that expansion modules are properly seated and that the total expansion chain does not exceed 7 modules. - Fault Code 7
- Configuration error: Mismatch between configured and detected expansion module types.
Verify that the physical expansion modules match the configuration defined in STEP 7 Micro/WIN. Replace any faulty or mismatched modules. - Fault Code 8
- Battery/capacitor low: Retentive memory backup power is insufficient.
For units with a memory cartridge, replace the battery cartridge. Ensure the CPU has been powered on long enough to charge the internal supercapacitor before a power loss occurs.
Frequently Asked Questions
What programming software is required for the 6ES7216-2AD23-0XB0?
This CPU is programmed using Siemens STEP 7 Micro/WIN software. The software communicates with the CPU via a PC/PPI cable or a CP card connected to the RS-485 port.
Can the CPU 226 be expanded with additional I/O modules?
Yes, the CPU 226 supports up to 7 expansion modules, allowing additional digital I/O, analog I/O, and special function modules to be connected via the integrated expansion bus.
What communication protocols does the 6ES7216-2AD23-0XB0 support?
The CPU supports PPI (Point-to-Point Interface), MPI (Multi-Point Interface), and Freeport (user-defined serial communication) protocols via its two RS-485 ports.
Does this CPU have a built-in real-time clock?
Yes, the CPU 226 includes an integrated real-time clock that supports time-of-day scheduling and time-stamped data recording.
What is the maximum program memory capacity of this CPU?
The 6ES7216-2AD23-0XB0 provides 8 KB of program memory and 5 KB of data memory, which can be supplemented using an optional memory cartridge for program storage and transfer.
Troubleshooting
CPU RUN LED does not illuminate after power on
Check the 24 V DC supply voltage at the CPU power input terminals. Measure voltage at the L+ and M terminals to confirm correct polarity and adequate voltage level. Inspect the internal fuse if accessible.
Ensure the 24 V DC supply is within the specified range and correctly wired. If supply voltage is confirmed correct and the CPU does not power on, the internal power supply section may be faulty and the unit should be sent for repair or replacement.
CPU is in STOP mode and cannot be switched to RUN
Check the SF (System Fault) LED status. Connect STEP 7 Micro/WIN and read the CPU error buffer to identify any active fault codes. Verify that the program memory is not empty or corrupted.
Clear any active faults using STEP 7 Micro/WIN, re-download the user program, and attempt to switch the CPU to RUN mode. If a fatal fault is present, perform a full memory clear (MRES) before re-downloading.
Communication failure between PC and CPU via RS-485 port
Verify the PC/PPI cable or communication adapter is correctly connected to Port 0 or Port 1. Check the communication settings in STEP 7 Micro/WIN (baud rate, station address). Inspect the RS-485 cable for damage or incorrect wiring.
Set the correct PPI baud rate (typically 9.6 kbps) and CPU station address in Micro/WIN. Replace the PC/PPI cable if damaged. Ensure no other devices on the network are using the same station address.
Expansion module I/O not responding correctly
Inspect the physical connection between the CPU and the first expansion module. Check that the expansion bus connector is fully engaged. Verify the module type matches the configuration in the program.
Re-seat the expansion modules and ensure the bus connectors are locked. Confirm that the total number of expansion modules does not exceed 7. Replace any expansion module that shows a fault LED or fails to communicate.
Retentive data lost after power cycle
The internal supercapacitor may not be fully charged, or the optional battery cartridge may be depleted. Check how long the CPU was powered before the power loss occurred.
Allow the CPU to remain powered for at least 24 hours to fully charge the supercapacitor. If a memory cartridge with battery backup is installed, replace the battery cartridge. Verify that retentive memory ranges are correctly configured in the program.
| Condition | Repair, Used, Refurbished, New in box (sealed) |
|---|
Related products
-
Siemens Simatic S7 6ES7431-0HH00-0AB0
Price range: € 359,00 through € 484,00 -
Siemens Simatic S7 6ES7221-1BH22-0XA0
Price range: € 75,00 through € 331,38