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3 cyclic communication, Cyclic communication -5, Cyclic communication – KEYENCE DL-EP1 User Manual

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- EtherNet/IP Compatible Network Unit DL-EP1 User’s Manual (IL) -

3-3

Cyclic communication

This section describes the cyclic communication functions and how to use them.

„

What is cyclic communication?

Cyclic communication is a function that exchanges data with the EtherNet/IP device

in a cyclic manner (at a set cycle).

In cyclic communication, data can be exchanged when one device successfully

opens a logical communication line called a "connection" with the other device.

The side which opens the connection is called the scanner, and the side to be

opened is called the adaptor. (The DL-EP1 is an adaptor.)

Cyclic communication is started in the following procedures:

(1) The scanner requests the adaptor to open the connection.

(2) The adaptor side checks compatibility.

(3) If no error occurs as a result the compatibility check, the adaptor opens the

connection.

(* If an error is found during the compatibility check, the adaptor does not open

the connection.)

"Checking the Device Compatibility" (Page 3-21)

Data is exchanged between the EtherNet/IP scanner, DL-EP1 and each sensor

amplifier as follows:

To carry out EtherNet/IP communication with a scanner which does not
support cyclic communication (Allen-Bradley SLC5/05 Series, etc.), use

"Message Communication" (Page 3-22).

(1) Request connection open

(3) Open connection

(2) Check
compatibility

Output data

Data reflected in the
scanner

Input data

The data output from the
scanner is stored by the
DL-EP1.

EtherNet/IP scanner

DL-EP1

Sensor amplifier

IN area

OUT area

Cyclic
communication

Data between
sensors is
refreshed

Cyclic
communication

Data between
sensors is
refreshed

Reference