Allen-Bradley DeviceNet 1761-NET-DNI, User Manual, Page: 96 / 101

1761-6.5
G-2 Glossary
DeviceNet Slave
A product whose data (or portion of) can be owned by DeviceNet Master.
DF1 Full Duplex
DF1 is a standard (open) point-to-point communication protocol. Virtually
all Allen-Bradley controllers (PLC-3
®
, PLC-5R
®
, SLC, MicroLogix) that
support an RS-232 communications port support DF1.
Explicit Messaging
A DeviceNet message which gets/sets device configuration information.
Heartbeat
A mechanism that allows a device, set of devices, or a connection to check
for operation or integrity. Also known as a watchdog.
Input Buffer
A set of 16-bit words that is available to a Master on DeviceNet. The input
buffer in DNI Series A is configurable from 1 to 16 data words (DNI Series
B is configurable from 1 to 32). The data in the input buffer originates from
the device connected to the RS-232 port (either by the DNI reading the data,
or the RS-232 device writing the data to the DNI). The input buffer
terminology is used because the data is input data to the DeviceNet Master.
Messaging
A general term that identifies the exchange of data between devices. The
two major types of DeviceNet messaging are:
•
I/O - DeviceNet master and DeviceNet slave.
•
Peer-to-Peer - Between compatible devices without a master’s
involvement.
Output Buffer
A set of 16-bit data words that is available to a Master on DeviceNet. The
output buffer in DNI Series A is configurable from 1 to 16 data words (DNI
Series B is configurable from 1 to 32). Output data received from the
DeviceNet master is forwarded (written) to the RS-232 device.
Peer-To-Peer
A type of communication where both devices are equal. These devices
communicate to each other without a third device to manage the transaction.
Profile Register
The location within the DNI where routing profile configurations are stored.
PCCC
Programmable Controller Communications Commands
UCMM
Unconnected Message Manager