Implemented protocols in UNIGATE® EL
Deutschmann Automation GmbH & Co. KG
47
UNIGATE
®
fieldbus gateway UNIGATE
®
EL - DeviceNet
™
V. 1.0
22.6.17
15.3.6 Modbus TCP (client)
After switching on the same behaviour as under TCP/IP (Client) beschrieben (see chapter
15.3.4).
Explanation
1.
The fieldbus SPS sends a request in Modbus RTU format, without checksum
2.
The UNIGATE
®
sends a TCP Frame as Modbus TCP Req. The transmission length is automati-
cally calculated by the UNIGATE
®
.
3.
The Modbus TCP Server (Remote) sends the required response back to the UNIGATE
®
4.
The UNIGATE
®
then sends the Modbus TCP Response in Modbus RTU-Format back to the
fieldbus SPS.
Note: A new request should only be started after completing the 4 steps.