Yaskawa SmartTrac DeviceNet Card - Manual (Page 7)

SMART TRAC DeviceNet Card
Technical Manual 3554-0070 Smart Trac DeviceNet Card
••
3
Smart Trac DeviceNet Card
General Capabilities
Adding the Smart Trac DeviceNet Card to your Smart Trac AC1 makes it fully
compatible with other industrial devices (i.e., drives, limit switches, operator
interfaces, programmable controllers) conforming to the DeviceNet standard. It
also complies with CAN (Controller Area Network) specification 2.0, parts A
and B, Standard Frame Identifiers.
The card also conforms to PC/104 specifications and has its own central
processing unit (CPU). It supports DeviceNet data rates of 125 Kbaud, 250
Kbaud and 500 Kbaud.
While DeviceNet supports up to 64 nodes identified by MAC IDs, the Smart
Trac DeviceNet card uses one MAC ID, leaving 63 other device nodes available
to be addressed.
The Smart Trac DeviceNet driver supports Polled I/O and Bit Strobed I/O
connections as well as explicit messaging. It supports all ODVA (Open
DeviceNet Vendor Association) approved devices.
Smart Trac AC1 on a DeviceNet
Network
With a Smart Trac DeviceNet card and driver installed and connected to a
DeviceNet network, the Smart Trac AC1 communicates in a Master/Slave
relationship (as opposed to peer-to-peer). A Smart Trac AC1 with an installed
Smart Trac DeviceNet card serves as Master of a DeviceNet network. The
Master gathers and distributes I/O data for the process controller. It also gathers
I/O data from Slave devices and distributes the data to Slave devices.
On a DeviceNet Master/Slave network, a Master device "owns" a Slave device.
A Slave device can be "owned" by only one Master. Except for a check for
duplicate MAC IDs, a slave cannot initiate communication transactions unless it
has been told to do so by its Master. The Master (in this case, the Smart Trac
DeviceNet card) scans its Slave devices based on a scan list that it contains. The
Slaves' MAC IDs appear in the Master's scan list of I/O addresses to be scanned
by the card at specified intervals.
Smart Trac systems support single master networks. Only one Smart Trac
DeviceNet Card is allowed per network.