MODEL CODE GUIDE
Overview
The complete ordering code from Siemens is called the MLFB (Machine Readable Product Code).
Take the common model 6ES7214-1AG40-0XB0 of the S7-1200 CPU 1214C as an example: 6ES7 is the SIMATIC S7 series prefix, 214 corresponds to the CPU 1214C, 1A represents the power supply and input and output type (DC/DC/DC), G4 represents the hardware generation version, 0XB0 is the configuration/version field at the end of the ordering code; it is not recommended to break away from Siemens official The MLFB table alone infers its full semantics.
code structure table
| field | Meaning | example |
|---|---|---|
| 6ES7 | SIMATIC S7 series prefix | — |
| 214 | CPU ordering code | CPU 1214C |
| 1A / 1B / 1H | Power and I/O type codes | 1A = DC/DC/DC |
| G4 / H5 | Hardware generation (G1 uses G4, G2 uses H5) | G4 = first generation, H5 = second generation (G2) |
| 0XB0 | Configuration/version field at the end of the ordering code | Check with Siemens official MLFB/product page |
CPU ordering code comparison table (S7-1200, can be used directly)
| code | corresponding model |
|---|---|
| 211 | CPU 1211C |
| 212 | CPU 1212C |
| 214 | CPU 1214C |
| 215 | CPU 1215C |
| 216 | CPU 1216C |
power supply/I/O typecodereference table
| code | Meaning |
|---|---|
| 1A | DC power supply / DC input / DC (transistor) output |
| 1B | AC power/DC input/relay output |
| 1H | DC power supply/DC input/relay output |
Selection Notes
The power supply type (AC/DC) must be consistent with the site power supply system. If the wrong selection is made, the device will not be powered on.
Relay output (1B/1H) is suitable for driving inductive loads such as contactor coils or loads of different voltage classes; transistor output (1A) responds faster and is suitable for high-demand switching or occasions requiring pulse output (such as stepper/servo control).
CPUs of different hardware generations (G4 for G1, H5 for G2) have differences in performance, storage capacity and size. When replacing, it is recommended to keep the same generation, or confirm the programming software version requirements of the new generation in advance. For details, see the S7-1200 G1 → G2 replacement page.
Frequently Asked Questions
What models are 6ES7214 and 6ES7215 respectively?
214 corresponds to CPU 1214C, and 215 corresponds to CPU 1215C; 1215C has larger program/data storage space than 1214C, and supports a second PROFINET communications port.
How to choose among the three codes 1A, 1B and 1H?
First confirm whether the site power supply is AC or DC, and then confirm the output load type: when driving inductive loads such as relays/contactors, relay output (1B/1H) is preferred, and when high-speed pulse output (such as stepper motors) is required, transistor output (1A) is preferred.
What should I do if part of the model is worn and unrecognizable?
You can provide a photo of the nameplate, or the I/O points, power supply method and other information of the existing system, and we will help verify the complete ordering code.
Need help confirming a part number or application?
Send the complete part number, BOM, nameplate or product photos. Documents and images can be shared through WhatsApp, Telegram or WeChat.
