After ten years of the original S7-1200 serving as Siemens' workhorse controller, the newly announced G2 series represents a fundamental rethinking of what a PLC can be. Let's examine exactly what's changed between generations.
Processing Speed: Cutting Response Time in Half
The G1 offers 85ns bit performance, the G2 slashes this to 40ns—less than half the processing time. This isn't just a specification improvement; it enables much faster scan times and quicker system responses that were impossible with the G1.
Memory: Breaking Past Previous Limitations
The memory constraints of the G1 series often required careful program optimization. The G2 dramatically expands these boundaries:
- CPU 1212C G2: 150kB program / 500kB data memory.
- CPU 1214C G2: 250kB program / 750kB data memory.
This expansion opens new possibilities for more sophisticated applications that weren't as feasible with the G1's memory constraints.
Physical Design: More Capability in Less Space
The G2 manages to pack more features into an even smaller footprint. The CPU 1212C shrinks from 90mm to 70mm, while the CPU 1214C reduces from 110mm to 80mm. The G2 also introduces a new high-density terminal block design with push-in wiring, addressing one of the G1's limitations in installation flexibility.
Motion Control: A New Level of Sophistication
The G1 offered basic motion control capabilities, but the G2 brings features previously reserved for advanced controllers. Where G1 focused on single-axis control, G2 adds coordinated multi-axis control and kinematics. This advancement enables sophisticated motion sequences that would have required a more advanced controller in the G1 era.
Network Communication: Ready for Modern Industry
The G2 supports up to 31 PROFINET devices and PROFINET IRT capability for synchronized control. Perhaps most significantly, the G2 introduces NFC functionality—completely absent from G1—enabling wireless access to diagnostics and configuration.
Safety Integration
The S7-1200 G2's approach to safety marks a significant advance, introducing fail-safe signal boards that mount directly on the CPU for safety applications up to PL e / SIL 3. The engineering experience has been streamlined by fully integrating safety programming into STEP 7 within TIA Portal, with ready-to-use certified program blocks available in the LSafe library.
High-Speed I/O: More Precise Control
The G2 increases the number of high-speed counter channels from 6 to 8, enabling more precise motion and position control applications.
For users of the original S7-1200, the G2 offers a clear upgrade path that maintains programming compatibility while delivering substantial improvements in every key performance metric. For new installations, it provides capabilities that simply weren't possible with controllers before.
Want to learn more? Watch our comparison video here!