Further Functions - Siemens PROFIBUS CP 1542-5 Manual

2.2

Further functions

Enabling /disabling DP slave - in the standard system
DP slaves can be activated and deactivated by the user program using system function
D_ACT_DP.
Diagnostics requests
As a DP master (class 1), the CP 1542-5 supports diagnostics requests of a DP master
(class 2).
Getting the bus topology in a DP master system
The CP 1542-5 operating as DP master supports the measurement of the PROFIBUS bus
topology in a DP master system using a diagnostics repeater (DP slave).
System function DP_TOPOL in the user program can instruct diagnostics repeaters to
measure the PROFIBUS BUS topology in a DP master system.
Time-of-day synchronization - time master or time slave
The CP 1542-5 can be enabled for time-of-day synchronization. As an alternative, the CP
can be configured as time master or time slave on PROFIBUS.
● Time master: The CP is synchronized using the time of day in the S7-1500 station and
outputs the time of day on PROFIBUS. The output interval can be set.
● Time slave: The CP receives time-of-day frames on PROFIBUS and outputs the time
within the S7-1500 station. The output interval within the S7-1500 station is set
permanently to 10 seconds.
Note
Recommendation for setting the time
It is advisable to set the time-of-day master so that time-of-day frames are sent at intervals of
approximately 10 seconds. This achieves as small a deviation as possible between the
internal time and the absolute time.
Web diagnostics
With the aid of Web diagnostics of the CPU, you read the diagnostics data from an S7
station via the Web browser on the PG/PC.
In terms of the CP, the Web pages provide the following information:
● Module and status information
● Special information on the DP master system (status of the DP slaves)
CP 1542-5
Manual, 11/2014, C79000-G8976-C326-03
Product overview
2.2 Further functions
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