SIL in Miniature Format
The smallest SIL3 absolute encoder (Cat. 3) currently available comes from TR Electronic.
Just 36 mm and fully safe
The CD_362+FS from TR Electronic is currently the smallest safe absolute encoder on the market that meets the high requirements of SIL3 or PLe with Category 3. With a diameter of 36 mm, TR Electronic delivers a redundant encoder system that includes two multiturn gearboxes and two sets of sensors. Even in this small encoder, TR’s wellknown safe bus protocols can be implemented.
Safe bus protocols without overhead
The safe encoders of the 362 series implement the safe bus protocol in compliance with standards and are certified for CANopen Safety and IO-Link Safety.
This differs from protocols typically transmitted via Industrial Ethernet: The safe bus protocols PROFIsafe, CIP Safety™, openSAFETY, and FSoE are generated securely directly within the encoder. They are then transmitted via an RS-485-based serial interface. Here, the “black channel” principle is adhered to: Reliable error detection is guaranteed regardless of the transmission channel.
The serial interface is intentionally kept simple. Few wires, robust transmission, unshielded cables, and a direct 5V power supply are optimally tailored for use with local controllers.
Standardized connection technology, on the other hand, would take up unnecessary installation space (M12 connectors, bus topology, 24-V power supply via separate wires).
Applications
Autonomous guided vehicles (AGVs) pose special challenges for the installed sensor technology. Multiple steering angles must be monitored. The entire steering function must meet safety requirements up to SIL 3, while installation space is extremely limited. Since the units are typically powered by rechargeable batteries, energy must be used efficiently.
The modular cabling of conventional (including safety-critical) fieldbuses offers no advantage in these highly integrated logistics devices. The control platforms are well-suited to controlling sensors and actuators via serial interfaces in a direct point-to-point connection. The security of the transmission is ensured by the certified protocols, which are also transmitted via this physical interface: The tested standards—such as those from PROFIsafe—are fully implemented, but transmitted via a different type of channel.
This allows users to rely on established and proven transmission protocols without having to deal with unnecessary components such as cabling.
Medical devices and equipment are becoming increasingly compact. At the same time, they are subject to stringent safety requirements, which is why only type-tested sensors with SIL classification are typically used in these applications. The compact design of TR Electronic’s CD_362+FS series also offers significant advantages for these devices. If a standard interface for communication with higher-level systems is required, the appropriate CIB2X+FS converter module can be used to convert the serial signals from up to 4 CD_362+FS encoders to a standard Ethernet interface. The converter module also follows the “Black Channel” principle, which ensures a reliable response to errors regardless of the transmission path.
With the CD_362+FS, TR Electronic is once again setting standards in the market for safe absolute encoders. This market-leading position, combined with over 40 years of experience in absolute encoders and over 20 years with SIL3-compliant sensor technology, offers an optimal solution for our customers.
The CD_362+FS family at a glance:
Mechanical specifications:
- Encoder diameter: 36 mm
- Typical overall length: 42 mm
- Available as a solid shaft and through-hole shaft / slip-on hollow shaft
- Blind-hole hollow shaft, slip-on hollow shaft: Form fit with a keyway in the clamping ring; shaft diameters 6, 8, 10, 12, 15 mm
- Solid shaft: Frictional fit, optionally positive fit with a key on the face. Shaft diameters: 6, 8, 10 mm
Interfaces:
- CANopen Safety
- IO-Link Safety
- SSI+SSI
- SSI + Incremental
via M12 connectors or cable glands
Secure interface protocol, standardized and tested via a serial connection:
- PROFIsafe
- CIP Safety™
- OpenSAFETY
- FSoE
This can be loaded directly into a controller by the customer.
Safety-oriented design
- Two-channel rotation sensing
- Rotation detection via two gearboxes and separate detections
- Monitored power supply
- Internal hardware diagnostics and consolidation into a secure transmission protocol
Press article including photograph