Siemens simatic c7-621, Руководство по установке оборудования

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2-24
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01
2.12 Clocks on the C7
The C7 devices have two software clocks:
S
One clock on the C7 CPU
S
One clock in the C7 OP
The clock of the C7 CPU is a software clock. This clock is independent of
the clock of the C7 OP.
When the unit is shipped, the following value is set:
DT#1994-0-01-00:00:00.
As an integrated clock, the C7 CPU clock can also function as the master
clock within the C7 I/O configuration.
You set and read the time as follows:
S
With a programming device using STEP 7
or
S
In the STEP 7 user program using SFC 0 “SET_CLK”. With SFC 1
“READ_CLK” you can read out the current time (refer to the reference
manual /235/).
If the power is turned off, the current time is saved in the non-volatile
memory. When power is turned on again, the clock continues to run starting
from the saved time.
When the power is turned off, the C7 CPU clock itself stops.
The clock on the C7 OP is independent of the clock on the C7 CPU. When
the power is turned off, the C7 OP clock stops.
When the device is shipped, the clock is set to the following value:
01.01.94 -00:00.
You set the time as follows:
S
Using a job in the user program and interface block.
or
S
Online by selecting the special display “Time/Date” if this was
configured.
Overview
Clock on the
C7 CPU
Default
C7 CPU Time
Master Clock
Setting and
Reading Out the
C7 CPU Clock
Clock Reaction to
Power Off
Clock on the
C7 OP
Default OP Time
Setting and
Reading Out the
C7 OP Clock
Installing and Preparing the C7