6
vacon • 23
EtherNet/IP
Tel. +358 (0) 201 2121 • Fax +358 (0)201 212 205
6.4.5
EtherNet/IP communication and connection timeout
The EtherNet/IP declares a watchdog the time within which both master and slave must send IO
back to each other. This watchdog time is a factor of the communication cycle time (cycle time x
timeout multiplier) and is set by the master. Minimum cycle time for VACON 100 EtherNet/IP is 4
milliseconds.
When an IO message is not received within the watchdog time, the timeout setting value is activated
and a fault is created after it elapses. This means that the panel parameter "Communication
timeout" (refer to chapter 4.2.4) is used as an additional timeout value. The same logic applies if a
connection is closed or the cable disconnects (link loss).
Figure 6. EtherNet/IP timeout logic with implicit connection (IO connection)
The explicit connections (TCP connection where PLC/user reads and writes data via CIP objects) will
generate fieldbus fault only if that connection has been used to write process data over Assembly,
Control Supervisor or AC/DC object. The explicit connection timeout is defined with TCP/IP Object's
attribute 13d "Encapsulation Inactivity Timeout".
We recommend that implicit connection is used for motor control and explicit connections for
"service data".
Communicating
Received packet within
watchdog time?
Communication
timeout zero?
Has additional
timeout elapsed?
Check
No
No
No
Yes
Yes
Implict Connection
established
FAULT!
Cable disconnected
Connection closed
11720_uk