Omron SYSMAC C200HW-PCS01-EV1, Operation Manual

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3. FINS commands to a PC Card Unit at the same Programmable Controller
are not transmitted to the Ethernet.
FA computer
Datagram (FINS response)
Datagram (FINS command)
PC Card Unit
C200HX/HG/HE
A datagram is the unit of data handled by UDP/IP communications through the
port specified for UDP communications. A communications service using UDP/
IP normally allocates unique communications ports to run the service.
Note The UDP/IP protocol does not provide communications control to ensure com-
munications reliability. Consequently, the FINS communications services using
the UDP/IP protocols cannot guarantee that any message arrived safely and
unaltered at the destination. Methods such as arrival confirmation processing to
ensure reliability must be programmed into the user application.
9-2 Using FINS Communications
This subsection outlines the methods for using FINS communications.
9-2-1 FINS Communications by Ladder Program
The processing flow for executing FINS communications from a ladder program
is explained below.
1, 2, 3... 1. The CMCR instruction is used to issue a FINS command.
PC Card Unit
User program
FINS
command
Using FINS Communications
Section 9-2