Specifications

48How to Create a New DP Master Project

The field ‘

Estimated bus cycle time

’ shows the expected minimum interval between two I/O data

exchanges with a slave. The cycle time depends mostly on the following factors:

baud rate

number of slaves configured in the master

I/O size of the configured slaves

max response time of each slave (max Tsdr)

number of acyclic requests, diagnostic telegrams and retries

other master stations sharing the same PROFIBUS network

Note:

The cycle time must be observed when setting the minimum slave interval and the

watchdog time. If the actual cycle time exceeds the settings for these parameters, the

communication cannot be started.

When using the estimated cycle time for adjusting min. slave interval and watchdog time

add sufficient time for communication of other masters and for acyclic data exchange

(DPV1 and diagnostic messages).

Communications Parameters of Master Settings

Parameter Meaning

Name

Shows the project specific name of the master

Baudrate

Transfer rate for the communication. Define a baudrate, which is

supported by all slaves.

FDL address

FDL address (station number)

Starting I/O

number

Module head address on the base unit

Note: the starting I/O number is only necessary for 'Copy POU' and 'I/O

Mapping POU'. It is not required for the download of the PROFIBUS

configuration. For online access the module is identified by the slot number

in the transfer setup.