Festo EXCM-10-***-E, Перевод оригинальной инструкции

Страница: 50 / 84

6 Operation
50 Festo – EXCM-10/-30-...-E-EN – 1612b – English
6.5 Control via Ethernet (CVE)
6.5.1 General remarks
With the function “Control via Ethernet” (CVE), the controller can be controlled via the Ethernet inter­
face. The controller is pre-parameterised for this purpose with the Festo Configuration Tool (FCT). It is
possible to start both homing and positioning jobs via CVE.
The controller can be actuated via the CVE interface in the record selection and direct mode operating
modes (
è
2.6 Operating modes).
6.5.2 Communication
The base for CVE communication is TCP data transfer (Transmission Control Protocol). The controller
acts as the server in this setup, while the PC application acts as the client, i.e. the PC application always
sends a request to the controller, which sends back a response (client-server principle).
The TCP connection is typically built up once and then remains in place as long as communication with
the controller is required. If the drive is in motion when the connection is ended, a Quick Stop function
is triggered.
The TCP port used can be set via the FCT. The port number 49700 is set at the factory.
Communication with the controller takes place via the CVE protocol. This must be imple­
mented in the PC application. Knowledge of programming TCP/IP applications is required
for this purpose.
CVE communication takes place via the CVE protocol (
è
6.5.3 CVE protocol), whereby control data are
written to CVE objects and status data are read out of SCE objects.
In the record selection operating mode, a record parameterised via the FCT is selected via CVE objects
and the positioning job is started.
In the direct mode, the target position in the direction of the X- and Y-axis as well as the speed and
acceleration values are written directly to CVE objects. The information on whether positioning should
take place absolutely or relative to the last setpoint position as well as the start of the positioning job is
also realised by writing to CVE objects.
Caution
Personal injury and material damage may result from other than intended use of the
CVE interface.
– The CVE interface is not real-time capable.
Control of the controller via Ethernet requires a risk evaluation by the user, interference-
free ambient conditions and securing of the data transfer, e.g. via the higher-order con­
troller.
Only use the CVE function in applications in which the lack of real-time capability
cannot pose risks.