Provides forty onboard digital points for medium-size S7-200 SMART applications.
Product Identification
6ES7288-1ST40-0AA1 is the Siemens SIMATIC S7-200 SMART CPU ST40. The DC/DC/DC CPU uses a 20.4 to 28.8 V DC supply with 24 onboard 24 V DC inputs and 16 onboard 24 V DC transistor outputs.
The CPU provides 40 KB of program and data memory together with the Ethernet and RS485 communication resources of the standard S7-200 SMART platform.
The 0AA1 article belongs to the V2.7 generation; Siemens states that it cannot be downgraded to V2.6 or earlier.
Engineering Data
| Manufacturer | Siemens |
|---|---|
| Exact article number | 6ES7288-1ST40-0AA1 |
| Product family | SIMATIC S7-200 SMART |
| CPU designation | CPU ST40 |
| CPU architecture | DC/DC/DC |
| Supply voltage | 20.4 to 28.8 V DC |
| Digital inputs | 24 onboard, 24 V DC |
| Digital outputs | 16 onboard transistor outputs, 24 V DC |
| Program and data memory | 40 KB |
| Industrial Ethernet interfaces | 1 |
| RS485 interfaces | 1 |
| Engineering software | STEP 7-Micro/WIN SMART |
| Firmware generation | 0AA1 hardware supports V2.7; no downgrade to V2.6 or earlier |
Functions
Uses transistor outputs for 24 V DC switching and pulse-oriented control duties.
Supports Ethernet and RS485 communications in the standard CPU platform.
Provides a documented 40 KB program and data memory allocation.
Applications
- Machine control requiring a higher onboard I/O count without changing platform.
- S7-200 SMART projects using 24 V DC transistor-output field devices.
- Ethernet-connected controller and HMI cells with an additional RS485 path.
- Controlled replacements supported by a Micro/WIN SMART project and full terminal record.
Lifecycle
- Archive the Micro/WIN SMART project, firmware, passwords, Ethernet and RS485 settings and expansion list.
- Record terminal commons, transistor loads and any high-speed I/O assignments before disconnection.
- Keep the 0AA1 V2.7 boundary visible; do not plan a downgrade to V2.6 or earlier.
- After exchange, verify every affected I/O point, communications and machine safety sequence.
About IndustryParts
https://www.industryparts.com/ST40 enquiries keep I/O scale and firmware generation together
IndustryParts records 6ES7288-1ST40-0AA1 with its exact DC/DC/DC architecture, 0AA1 generation and installed project evidence.
- ST40 identity preserved
- I/O and firmware recorded
- Project evidence reviewed
FAQ
Can 6ES7288-1ST40-0AA1 be replaced by an ST30 without rewiring?
No direct equivalence should be assumed because onboard I/O count, memory and terminal assignments differ.
What software evidence should accompany a 6ES7288-1ST40-0AA1 enquiry?
Provide the Micro/WIN SMART project, CPU firmware, password status, expansion list and communication settings.
Can the 0AA1 ST40 run firmware V2.6?
No. Siemens states that 0AA1 CPUs cannot be downgraded to V2.6 or earlier.
Why must output loads be documented before exchange?
Transistor outputs have defined voltage, current, common and protection requirements that must match the installed field devices.
What final test should follow an ST40 replacement?
Verify project checksum, networks, expansion modules, every affected I/O point and a controlled complete machine cycle.
