Eaton easySafety, Manual

Page: 529 / 695

Introduction to the ea s yNet
network
525
02/16 MN05013001Z EN
Transfer behaviour of the NET stations
Prior to every circuit diagram cycle the network data is
written from the NET receive buffer to the operand image of
the standard circuit diagram . The standard circuit diagram
processes the next cycle with this data. At the end of the
circuit diagram cycle the refreshed network data from the
operand image is written to the NET send buffer and then
transferred.
Reading and sending the data via the NET
The communication process of a NET station reads every
message on the NET and checks whether any messages are
meant for its own address (NET ID). If yes, they are
transferred to a receive memory.
If the content of the send memory changes, a message is
sent provided that no other message is being transferred on
the NET at this time. The NET ensures that each station can
send its messages. This means that each station must
maintain a delay time between the sending of messages.
The pause time increases the higher the number of stations
and the lower baud rate setting.
The number of NET stations present is recognised by every
station by means of a “sign of life” signal.
h
The following applies to a fast message transfer:
• Set the fastest possible baud rate to suit the network
length and cable cross-section.
• Fewer messages means faster messages.
• Avoid transferring (download/upload) a circuit diagram
while the NET stations are in RUN mode.