Rev. B, September 2023 57
Moog X700 Series 2-way Servo Cartridge Valves
Modern automation technology is characterized by an
increasing decentralization of processing functions via
serial data communication systems. The use of serial bus
systems in place of analog signal transfer guarantees
greater system flexibility with regard to alterations and
expansions.
There is also considerable potential for saving project
planning and installation costs in many areas of industrial
automation. Further possibilities of parameterization,
better diagnostics and a reduction of the number of
variants are advantages which have only been made
possible by the use of fieldbuses.
VDMA Profile Fluid Power Technology
In a working group within the VDMA (German Machinery
and Plant Manufacturers‘ Association), a device profile
was created in collaboration with numerous well-known
hydraulic system manufacturers. This profile describes
the communication between hydraulic components via a
fieldbus and defines uniform functions and parameters.
In this way, a standardized exchange format covering all
manufacturers was created.
The Moog X700 Series Servo Cartridges can be equipped
with the following fieldbus interfaces: CANopen or
EtherCAT.
CANopen
According to ISO 11898, IEC/EN 61800-7 CAN bus was
originally developed for use in automobiles, but has also
been used for years in a variety of industrial applications.
The CAN bus is primarily designed for transmission
reliability and speed.
The CAN bus has the following general features:
• Multi-master system: Each node can transmit and
receive
• Topology: Line structure with short stub cables
• Network expansion and transmission rates:
- Up to 25 m (80.4 ft) at 1 Mbit/s
- Up to 5,000 m (16,090 ft) at 25 kbit/s
• Addressing type: Message-orientated via identifiers.
Priority assignment of messages possible via
identifiers
• Safety: Hamming distance=6, i.e. up to 6 individual
errors per message are detected
• CiA408: Device profile fluid power technology for
proportional valves and hydrostatic transmissions
• Other used CiA specifications: CiA102, CiA301,
CiA303, CiA305 and CiA306
• Bus physics: ISO 11898
• Maximum number of nodes: 127
EtherCAT
According to IEC 61800-7 EtherCAT was developed as
an industry bus based on Ethernet to meet the increasing
demands for faster cycle times. The EtherCAT bus is
designed for high data transmission rates and fast cycle
times.
The EtherCAT bus has the following features:
• Single-master system: The master initiates
communication. The slaves react only upon request
• Topology: Line, star, tree and ring structure based on
the daisy chain principle
• Network expansion and transmission rates: 100 m
(321.8 ft) between two nodes at 100 Mbit/s
• Addressing type: Address-orientated, one telegram
for all nodes
• Bus physics: Fast Ethernet 100 Base Tx
• Maximum number of nodes: 65,535
ELECTRONICS
BACKGROUND
Fieldbus Interface