8
Fea tu r es Section 1-2
Automatically Adjusting the PLC's Internal Clock at Regular Intervals
Operation Use the automatic clock adjustment function.
With the automatic clock adjustment function, the SNTP server's clock is
taken as the standard for automatically adjusting the built-in clock of the PLC
connected to the Ethernet Unit. The adjustment can be regularly executed at
a specified time (once a day) and it can be executed each time by the ladder
program.
To use the automatic clock adjustment function, there must be a separate
SNTP server on the network. Aside from the IP address, the host name use d
for DNS service can be specified for the SNTP server.
Reference SECTION 5 Automatic Clock Adjustment Function in the Operation Manual
Construction of Applications
1-2 Features
Compatibility and Speed
The transmission medium has been upgraded to 100Base-TX, whi le compati-
bility with the functions and application interfaces of the existing Ethernet Unit
models (CS1W-ETN01, CS1W-ETN11, and CJ1W-ETN11) has been main-
tained. Moreover, processing speed has been improved so that the system
response performance for the same FINS message applications is now up to
four times faster.
Various Protocols Available on Ethernet
A variety of protocols makes available a wide range of applications for use on
an Ethernet network. The protocols that can be selecte d incl ude send ing and
receiving data by TCP/IP or UDP/IP (socket services), sending and receivin g
commands by OMRON's standard protocol FINS, transferring files by FTP,
sending and receiving e-mail by SMTP/POP3, and automati cally adjusting the
PLC's internal clock by SNTP.
A communications service can be selected acc ording to need, allowing the
PLC to be flexibly integrated with the Ethernet information network.
Communications by UDP/IP and TCP/IP (Socket Services Function)
The standard Ethernet protocols, UDP/IP and TCP/IP, are supported, making
it possible to communicate with a wide range of devices, workstations, com-
puters, and Ethernet Units from other manufacturers.
Up to eight ports can be used for various protocols, enabling the use of vari-
ous applications.
Simplified Socket Services
Without using the CMND(490) instruction, the socket services function for
TCP or UDP can be simplified by presetting parameters and using dedicate d
bits. In addition, the size of received data accumulated in the recep tion buffer
is now stored, and a Data Received Flag has been added. These new fea-
tures eliminate the need for ladder programs to monitor the timing for comple-
tion of instructions and socket service processing, and thus reduce the
amount of labor required for program development.