2.16 Details on Protocols
No-protocol Communications
2-410
No-protocol Communications
Message Structure
When no-protocol communications is set as the communications protocol, application data is handled as a
general-purpose message. When sending and receiving data, each message consists of two fields: a header
and the application data field.
The header is for TCP/IP and UDP/IP connections and is used only for Ethernet communications. User
programs do not need to be aware of this header because it is automatically appended and removed in the
218IFD.
The application data field can be formatted as required by the application. The application data field has
the following message structure.
The difference compared to using the general-purpose messaging mode with the Extended MEMOBUS
protocol is that the 218 header is not appended before the application data.
General-purpose Message Commands
General-purpose message commands can be set as required by the application.
General-purpose Binary Mode
In no-protocol communications, the values of the MW hold registers in the Machine Controller are sent
and received in the application data field.
Communications Protocol
Code
Reference
No-protocol
BIN
General-purpose Binary Mode (page 2-410)
No-protocol
ASCII
General-purpose ASCII Mode (page 2-411)
Ethernet communications will use either binary or ASCII data based on the code setting in the connec-
tion parameters.
Header
Application data
General-purpose Message
Application will use only this field.
TCP/IP header
(only for Ethernet
communications)
Note
7 • • • • • • • • • 0
(L)
(H)
(L)
(H)
(L)
(H)
(L)
(H)
Command
Contents of
MW
Contents of
MW
+ 1
Contents of
MW
+ n - 1
The contents of the MW
to
MW
+ n -1 hold registers in the
Machine Controller are set in these fields.
No response is returned when a message is sent.