Datasheet

TMC8460-BI Datasheet (V100 / 2016-Sep-01)

2 Principles of Operation

2.1 Key Concepts

2.1.1 General Information on EtherCAT

EtherCAT (Ethernet in Control and Automation Technology) has been developed and patented by

Beckhoff. It is an Ethernet-based technology for data transmission and application control in real time.

All process data for all connected nodes are transmitted in a single frame. All nodes connected to the

bus interpret, process, and modify their data „on the fly“. Ethernet frames are not buffered inside a

node but are directly forwarded with minimum additional delay. Maintaining a strict master-slave

communication, data exchange utilizes mailbox mechanisms and PDOs (Process Data Objects).

To ensure real-time behavior, frame processing and forwarding requires special hardware.

This special hardware is called ESC (EtherCAT Slave Controller) like the Trinamic TMC8460, TMC8461, or

TMC8462.

EtherCAT does not require software interaction for data transmission inside the slaves. EtherCAT only

defines the MAC layer (similar to CAN). Higher layer protocols are implemented in software on

microcontrollers connected to the ESC.

The ETG takes care for standardization activities and conformance testing. EtherCAT is integrated into

the following major standards: IEC 61158 (protocols and services), IEC 61784-2 (communication profiles

for devices), IEC 61800-7 (drive profiles and communication), SEMI standard E54.20 (since 2007).

For detailed information on the EtherCAT technology, the EtherCAT core mechanisms, and major features

we refer to the official standard documentations and guidelines available from ETG (www.ethercat.org,

ETG.1000), IEC (http://www.iec.ch, see numbers above), and Beckhoff (http://www.beckhoff.de, technical

specification).

2.1.2 EtherCAT Slave Controller (ESC)

The TMC8460 is a standard-conform dedicated EtherCAT Slave Controller providing EtherCAT MAC layer

functionality to EtherCAT slaves.

It connects via standard of-the-shelf Ethernet PHYs to the physical medium and provides a digital control

interface to a local application controller while also providing the option for standalone operation.

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CAT

EATURES

• Ethernet PHY interface: 2 x MII

• 6 FMMUs & 6 Sync Managers

• 16 Kbyte Process Data RAM

• 64 bit Distributed Clocks

• I²C interface for external EEPROM

• SPI Process Data Interface (PDI) with up to 30Mbit/s / optional Device Emulation mode