Overview and Purpose
The NAMC-ECAT is an EtherCAT slave module in the Advanced Mezzanine Card (AdvancedMC or AMC) form factor. It is available as single compact, mid or full-size module.
With the NAMC-ECAT, any embedded system based on the MicroTCA standard can be integrated as a slave node in an existing high performance, real time field bus system based on EtherCAT. The NAMC-ECAT offers three RJ45 connectors on its front panel to build networks with line, star and branch topology. Sensor and actor data transfer within the MicroTCA system is based on PCI Express.
The goal of EtherCAT (Ethernet for Control Automation Technology) is to have a low price, high speed real-time field bus system with very short cycle times and exact synchronisation, which is important in industrial automation applications. EtherCAT can be used in a broad range of applications and is completely compliant to the current Ethernet standard, but does not have the latency and overhead issues of Ethernet.
An EtherCAT network has an EtherCAT Master, which controls the network of EtherCAT slave devices. Up to 65535 EtherCAT slaves can be integrated with a distance of up to 100m to each other, totaling n x 100m for the whole network. The topology of the field bus network can be line, star and branch.
To use a MicroTCA system as the EtherCAT master, only a standard CPU AMC module running the Master EtherCAT software and a standard Ethernet are needed.
To use a MicroTCA system as an EtherCAT slave, a special AMC module is needed, which adds and drops information on the fly in real time into the EtherCAT bit stream. This is the function of the NAMC-ECAT.
MicroTCA systems as slave devices of an EtherCAT network can be used for image and sensor preprocessing or for complex control applications such as robotics. In addition, EtherCAT also allows the transfer of standard Ethernet packets. Therefore, all the new features of remote control and management functions of MicroTCA systems can be used over the same cable.
A key component of the EtherCAT slave card, NAMC-ECAT, is the ESC (EtherCAT Slave Controller) as the interface between the EtherCAT bus and the user application. This module uses the EtherCAT-ASIC ET1100 from Beckhoff as ESC.
The ESC ET1100 has 8 kByte RAM to simultaneously exchange data between the EtherCAT network and the Process Data Interface (PDI). The PDI is directly accessible from other AMC modules via the backplane PCIe interface.
Simultaneous updates of the registers from the EtherCAT interface and the PDI side are implemented.
The EtherCAT physical connection consists of three ports on the front panel supporting all defined topologies of an EtherCAT network. Each port has an auto forwarder and loop back function, which detects a broken cable and if a second Ethernet cable is used, allows a redundant configuration and continuation of data transfer.