10 Further Notes on Operation
B4A
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65
CP 443-1 Advanced for Industrial Ethernet / Manual Part B4A
Release 01/2007
C79000-G8976-C193-06
Forwarding the Time-of-Day Message
You can configure the direction in which time-of-day messages are forwarded in
STEP 7 / NCM S7 in the properties dialog of the CP.
The CP 443-1 Advanced forwards time-of-day messages in the following directions
depending on the project engineering configuration:
S
From the CPU to Industrial Ethernet over the K bus
when the local CPU is time master (SIMATIC mode only) or when the time of
day is forwarded by a difference CP on the K bus.
S
From Industrial Ethernet over the communication bus to the CPU
when one of the following components is the time master:
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In the SIMATIC mode:
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a remote CPU 41x
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a SIMATIC NET time transmitter
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a CP 1430 TF
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an NTP server when using the NTP mode
As default, time
−
of
−
day synchronization is not activated for the CP and it does not
therefore forward the time. However, the internal clock of the CP is also
synchronized in this situation when a time
−
of
−
day frame is received from the
communication bus or from Industrial Ethernet.
Synchronization using one of the two modes described here must be configured in
STEP 7 in the properties dialog of the CP
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”Time-of-Day Synchronization” tab.
For more detailed information on the parameters and options, please refer to the
online help in the properties dialog.
Coordinating Forwarding of the Time of Day with Several CPs
If there is more than one CP in a station connected to the same network, only one
of these CPs is allowed to pass on time
−
of
−
day messages.
You can therefore made the following settings in the configuration:
S
Automatic
The CP receives the time frame from the LAN or from the station and forwards
it to the station or the LAN.
If several CPs are being operated in the station, this automatic setting can lead
to collisions. To avoid this, you can specify the direction in which the frame is
forwarded:
S
From station to LAN
S
From LAN to station
