Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 14)

About This Manual P–3
1770Ć6.5.16 Ċ October, 1996
Term Definition
local node The node sending the command
node The point at which devices, such as programmable controllers,
interface to the network. Each device on a network must have a
unique node address.
In some AllenĆBradley documentation, you may find the term station
used in place of the term node.
physical link Cable and associated hardware, such as transmitter and receiver
circuits.
PLC controller An AllenĆBradley programmable controller. See programmable
controller.
protocol Set of programming rules for interpreting the signals transmitted over
the physical link by nodes.
programmable
controller
a solidĆstate control system that has a userĆprogrammable memory
for storage of instructions to implement specific functions such as I/O
control, logic, timing, counting, report generation, communication,
arithmetic, and data file manipulation. A controller consists of central
processor, input/output interface, and memory. A controller is
designed as an industrial control system.
remote node The node sending the reply to the local node
Abbreviation Definition
ACK acknowledgement. In communication, ACK is a control code sent by
the receiving node to indicate that the data has been received
without error and the next part of the transmission may be sent.
DH+ Data Highway Plus. AllenĆBradley proprietary network protocol.
NAK negative acknowledgement.
Publication Name Publication Number
DH/DH+/DH II/DH485 Cable Installation Manual 1770Ć6.2.2
DH Overview Product Data 1770Ć2.39
DH+ Overview Product Data 1785Ć2.6
SCADA System Selection Guide AGĆ2.1
SCADA System Application Guide AGĆ6.5.8
Terms and Abbreviations
Related Publications