Siemens SIMATIC S7‑1500F with F‑TM Count vs Istec SpeedSys® 300

Why forward-thinking OEMs, integrators, and end users choose SpeedSys® 300

Established brands often continue to build on existing architectures for many years, leaving limited room to incorporate user feedback or modern application requirements. Istec, however, has developed its latest systems from the ground up, with a clear focus on today’s needs in machine protection and monitoring.

As a result, SpeedSys® 300 not only covers the core overspeed protection functions traditionally expected from established solutions, but also extends them with a compact modular design, support for multiple sensor types, configurable outputs, modern communication options, and clearly specified response characteristics. This allows users to implement proven protection concepts while benefiting from additional flexibility and transparency that are increasingly important in both new installations and retrofit projects.

SIMATIC S7‑1500F with F‑TM Count

Istec SpeedSys 300

Proven-in-use

The SIMATIC S7‑1500F with F‑TM Count is used in industrial automation environments where safety‑related counting, speed monitoring, and position detection are integrated into a PLC‑based safety system. The solution is applied in machine and process automation architectures based on the Siemens TIA Portal ecosystem.

Certified by design

SpeedSys® 300 is designed with functional safety embedded directly into the system architecture. SIL 2 and SIL 3 capability are integral to the product design and depend on the applied redundancy configuration, rather than being added as an external system layer.
(Background on this approach: Het verschil tussen SIL-certificering door ontwerp en proven in use)

System‑integrated protection concept

Overspeed and speed‑related monitoring functions are implemented as part of the S7‑1500F safety PLC architecture. The F‑TM Count module operates in combination with a failsafe CPU, with evaluation, logic, and shutdown actions handled within the PLC safety program.

Standalone protection concept

Each SpeedSys® 300 module performs a complete overspeed protection function independently, clearly separating protection functionality from control and monitoring systems.

Integrated redundancy approach

Redundancy is achieved at system level through PLC architecture, failsafe CPUs, and configuration within the TIA Portal environment. The F‑TM Count module itself is designed as a single measurement module and does not perform internal voting independently.

Modular redundancy approach

Redundancy is achieved by combining multiple SpeedSys® 300 modules, supporting flexible 1oo1, 1oo2, or 2oo3 voting architectures at system level.

Integrated safety outputs

Safety‑related outputs are not generated directly by the F‑TM Count module. Shutdown and actuator control are implemented via separate failsafe digital output modules within the S7‑1500F system.

Integrated safety I/O

Safety relays and a safety‑related analog output are available directly on the device, reducing external safety hardware.

Backplane‑based system design

The F‑TM Count module is installed on the SIMATIC S7‑1500 or ET 200 platform and operates as part of a rack‑based PLC I/O system using a shared backplane.

Standalone and distributed installation

SpeedSys® 300 is installed as an individual DIN‑rail mounted device. Multiple units can be mounted side‑by‑side to implement redundancy concepts without requiring a shared rack, backplane, or central baseplate.

Communication for diagnostics

Diagnostics and status information are available via the HIMax system bus and are configured and monitored using the SILworX engineering tool.

Communication for diagnostics

Modbus RTU over RS‑485 is provided for monitoring and diagnostics only and is not part of the safety function.

System‑level protection architecture

Speed and counting functions are safety‑rated only when used within a complete S7‑1500F safety configuration. The F‑TM Count module itself does not operate as a standalone overspeed protection device and depends on the PLC safety program and system configuration to perform protective functions.

Compact and practical design

The compact footprint supports space‑constrained installations and retrofit projects, while maintaining full overspeed protection functionality within a single module.

Lifetime Support

SpeedSys 300 delivers a clean architectural separation between control and trip logic ensuring uncompromised protection compared to integrated systems.

SIL3 by Design

Adapt as needed: from single-channel setups to fully redundant 2oo3 architectures, SpeedSys 300 supports stepwise scalability at every stage.

Compact Footprint and Seamless Integration

Engineered for space-limited panels and demanding environments, it’s ideal for both retroﬁts and new installations.

FAQ

Is the SpeedSys 300 a standalone system?

Yes, it’s an independent overspeed protection system, aligned with the requirement that overspeed protection be separate from the control system.

Do both systems support redundant architectures such as 2oo3?

Yes. Both systems can support 2oo3 architectures: SpeedSys® 300 achieves this by using multiple independent devices with external hard‑wired voting, while Siemens SIMATIC S7‑1500F with F‑TM Count can realize 2oo3 at system level through the PLC configuration, sensors, and safety logic rather than within a standalone overspeed device.

Which system support Profibus-based DCS integration?

Neither system supports Profibus‑based DCS integration.
SpeedSys® 300 provides Modbus RTU over RS‑485 for monitoring, while Siemens SIMATIC S7‑1500F with F‑TM Count integrates via the PLC’s PROFINET/PROFIsafe communication; Profibus support is not specified in the available documentation for either solution.

Accuracy disclaimer

All of our comparison pages have been filled in to the best of our knowledge, using publicly available sources. However, we cannot guarantee that they are fully up-to-date or completely correct.

Istec ensures the availability and safety of your rotating machinery by providing the most convenient and accessible hardware solutions, delivered by the world’s leading vibration and speed sensing experts.

	Siemens SIMATIC S7‑1500F with F‑TM Count	Istec SpeedSys® 300
Key features	Safety‑rated counting and speed monitoring integrated in PLC architecture; configuration via TIA Portal; flexible system integration.	Overspeed, underspeed and acceleration detection; compact standalone design; modular redundancy; Modbus diagnostics.
Number of relays	No relays on F‑TM Count module; safety outputs provided by separate failsafe digital output modules	2 safety relays per module plus additional signal outputs
Frequency range	Depends on encoder and configuration; explicit overspeed frequency range not specified.	0.0025 Hz – 35 kHz
Hardware response time	Not specified in available documentation.	< 8 ms (relay output)
Voting system	Voting and safety logic implemented in PLC safety program; F‑TM Count module itself does not perform independent voting.	1oo1 (single module); 1oo2 or 2oo3 using multiple modules (external voting).
Number of inputs (active)	Counting inputs provided by F‑TM Count module; safety evaluation performed in PLC program. Number of active inputs per safety function not explicitly specified.	1 input per module (only one sensor input active at a time)
Outputs	Safety‑related shutdown and actuator control via external failsafe I/O modules within the S7‑1500F system. No analog or frequency outputs on the F‑TM Count module itself.	• 1 × safety‑rated 4–20 mA analog output • 1 × binary output • 1 × frequency output • Modbus RTU (RS‑485, diagnostics only)
Input voltage	Supplied via SIMATIC S7‑1500 / ET 200 system; specific input voltage for counting inputs not explicitly specified.	24 VDC (18 – 36 VDC
Functional safety	Safety‑rated operation only as part of a complete S7‑1500F safety system; SIL level depends on overall PLC architecture and configuration.	SIL 2 / SIL 3 capable; functional safety embedded in system design.
Stand‑alone protection	Not specified in available documentation; depends on PLC CPU, safety program, and external I/O.	Yes – each module performs a complete overspeed protection function independently.
Relay information	Not specified in available documentation (no relay outputs on F‑TM Count).	2 × safety relays (DPST); max. 30 VDC / 2 A (resistive load).
Rack / backplane mounting	Yes – installed as part of SIMATIC S7‑1500 / ET 200 rack‑based PLC system.	Optional 19‑inch rack for mechanical mounting only; no shared backplane or internal bus.
Reserve scalability	Scalability achieved through PLC system expansion, additional F‑modules, and safety program configuration.	Scalable from single module (SIL 2) to redundant multi‑module SIL 3 configurations.