PLC selection guide
S7-1200 vs S7-1500: how to choose the PLC platform
Compare SIMATIC S7-1200 / G2 and S7-1500 by machine scale, I/O, performance, motion, safety, networking and lifecycle—not only CPU price.
Choose the platform from the complete automation architecture. S7-1200 / G2 is evaluated for compact and modular machines; S7-1500 is evaluated when workload, architecture, motion, safety, diagnostics or future scale needs a more capable platform. The exact boundary depends on the CPU, modules and software environment.
01What is the direct answer for this plc selection guide?
Choose the platform from the complete automation architecture. S7-1200 / G2 is evaluated for compact and modular machines; S7-1500 is evaluated when workload, architecture, motion, safety, diagnostics or future scale needs a more capable platform. The exact boundary depends on the CPU, modules and software environment.
02What information should a buyer prepare for plc selection guide?
Prepare functional description and operating modes, i/o list by signal type and location, cycle-time and technology-function requirements, motion, safety and redundancy scope, network topology and third-party interfaces. Missing information should be recorded as an assumption before release.
03Which decisions can change the result?
Review program and cycle duty, i/o and distribution, motion and safety, networks and integration. The complete project and article-number context determines the final answer.
PLC selection guide framework
Six checks for this decision
Apply these checks to s7-1200 vs s7-1500: how to choose the plc platform so assumptions are visible before the BOM, drawing, procurement release or shutdown plan is approved.
Program and cycle duty
Estimate logic size, execution time, technology functions, data handling and future change—not only the current I/O count.
I/O and distribution
Map central and remote I/O, safety signals, specialty modules, station locations and required diagnostics.
Motion and safety
Define axes, positioning, synchronization and functional-safety responsibility before choosing the CPU family.
Networks and integration
List PROFINET devices, third-party protocols, SCADA or cloud interfaces and plant-network ownership.
Engineering environment
Confirm TIA Portal version, libraries, licenses, team capability, source ownership and installed-base standards.
Lifecycle and expansion
Check product generation, spare strategy, panel space, memory and the cost of changing platform later.
Buyer checklist
Inputs for plc selection guide
- Functional description and operating modes
- I/O list by signal type and location
- Cycle-time and technology-function requirements
- Motion, safety and redundancy scope
- Network topology and third-party interfaces
- Software version, libraries and source ownership
Common mistakes
Risks in this decision
- Choosing from I/O count alone
- Ignoring generation-specific modules and software
- Treating safety as an accessory added after CPU selection
- Comparing CPU price without engineering and lifecycle cost
Common PLC selection guide searches
Answers before the technical release
These answers summarize the guide. Final compatibility, ratings, accessories and availability still require the exact article number and current source information.
What is the direct answer for this plc selection guide?
Choose the platform from the complete automation architecture. S7-1200 / G2 is evaluated for compact and modular machines; S7-1500 is evaluated when workload, architecture, motion, safety, diagnostics or future scale needs a more capable platform. The exact boundary depends on the CPU, modules and software environment.
What information should a buyer prepare for plc selection guide?
Prepare functional description and operating modes, i/o list by signal type and location, cycle-time and technology-function requirements, motion, safety and redundancy scope, network topology and third-party interfaces. Missing information should be recorded as an assumption before release.
Which decisions can change the result?
Review program and cycle duty, i/o and distribution, motion and safety, networks and integration. The complete project and article-number context determines the final answer.
What are the common mistakes in plc selection guide?
Choosing from I/O count alone; Ignoring generation-specific modules and software; Treating safety as an accessory added after CPU selection; Comparing CPU price without engineering and lifecycle cost.
How should the final answer be verified?
Confirm current ratings, compatibility, lifecycle, mandatory accessories and application limits against the complete Siemens article number and cited manufacturer information before quotation or technical release.
Continue the decision
Pages related to plc selection guide
Technical references
Sources for this guide
Ratings, compatibility and lifecycle details referenced in s7-1200 vs s7-1500: how to choose the plc platform must be verified again against the exact article number at quotation.
Apply this guide