Bray 70 Series SERVO PRO DeviceNET - Manual (Page 9)

S70 DeviceNet Servo Installation & Maintenance Manual
2000 BRAY CONTROLS Page 8 of 24
3. DeviceNet Interface
The S70 Servo is an ODVA (Open DeviceNet Vendor Association) compliant product. The
ODVA certification ensures that the S70 Servo can operate on any DeviceNet network and
supports all of the features required to operate cooperatively on a network with mixed devices
which are also ODVA compliant.
3.1 DeviceNet Network
DeviceNet is a low-level network that provides connections between simple industrial devices
(sensors, actuators) and higher-level devices (controllers) such as the S70 Servo. DeviceNet
provides:
A cost effective solution to low-level device networking
Access to intelligence present in low-level devices
Master/Slave and Peer-to-Peer capabilities
The list below presents a summary of the Physical/Media specific characteristics of DeviceNet:
Trunkline-dropline configuration
Support for up to 64 nodes
Node removal without severing the network
Simultaneous support for both network-powered (sensors) and self-powered (actuators)
devices
Use of sealed or open-style connectors
Protection from wiring errors
Selectable data rates of 125k baud, 250k baud, and 500k baud
Adjustable power configuration to meet individual application needs
High current capability (up to 16 amps per supply)
Operation with off-the-shelf power supplies
Power taps that allow the connection of several power supplies from multiple vendor that
comply with DeviceNet standards
Built-in overload protection
Power available along the bus: both signal and power lines contained in the trunk-line
3.1.1 Network connections, terminations, power, and limits
Devices on the network are connected as shown in Figure 4. The network consists of two types
of cable; a trunk-line cable and a drop cable. The Trunk line cable is a thicker cable that spans
the length of the network. A device is attached to the Trunk line directly by using either a Tap or
indirectly by using a Tap and a drop cable. The Drop cable is not as thick as the Trunk line and
is only used to connect a single device to the bus.
A terminator of 121 ohms is required at each extreme end of the trunk. The terminator is
attached to the end of the trunk and not to the end of a cable drop.