Omron CJ1W-EIP21 用户手册

The EtherNet/IP Unit or built-in EtherNet/IP port can obtain the clock informa-
tion from the SNTP server (see note 1) at a particular time or when a desig-
nated bit turns ON and then refresh the internal clock information of the CPU
Unit to which it is mounted (referred to as the local CPU Unit).

(1) The SNTP (Simple Network Time Protocol) server is used to control the

time on the LAN.

(2) An error will occur in the following CPU Units when the automatic clock

adjustment function is executed under the conditions shown in the table.

(3) The manufacturing date can be determined from the lot number on the

side or top corner of the CPU Unit. 

(4) The lot numbers are as follows:

YYMMDDnnnn, in which YY indicates the last two digits of the year, MM
the month, DD the day, and nnnn the serial number.

(5) In accordance with SNTP protocol specifications, automatic adjustment

will not be possible from February 7, 2036. In EtherNet/IP Units or built-
in EtherNet/IP ports, this function will no longer operate from February 7,
2036 (an error message will not be displayed).

Intranet

SNTP server

Automatic clock adjustment

Ethernet

EtherNet/IP Unit or 
built-in EtherNet/IP port

Clock data is obtained from the   
SNTP server and written at a particular  
time or when a designated bit turns ON.

The clock information can be broadcast to other CPU Units on the same Network.

24: 00: 00

24: 00: 00

CPU Units manufactured on or 
before January 31, 2003 (lot num-
bers 030131 or earlier):
CJ1G-CPU

@@

H

CJ1H-CPU

@@

H

CS1G-CPU

@@

H

CS1H-CPU

@@

H

When the CPU execution mode is set to other 
than normal mode (priority peripheral servicing 
mode, parallel processing with synchronous 
memory access mode, or parallel processing 
with asynchronous memory access mode).

AND

When the CPU Unit operating mode is set to 
RUN or MONITOR mode.