Siemens MICROMASTER 411 - Manual (Page 150)

10 Engineering Information Issue 03/01
MICROMASTER 411 & COMBIMASTER 411 Operating Instructions
150 6SE6400-5CA00-0BP0
NOTES:
The PROFIBUS Module (see Section 8.4) can only be fitted and removed from
the inverter when the inverter is powered off.
The PROFIBUS Module must be connected to the drive using the cable
supplied.
The data structure for communication over PROFIBUS-DP can be either PPO type
1 or PPO type 3 as specified in VDI/VDE 3689. This means in practice that process
data (control words, setpoints in the transmitted telegram and status words, actual
values in the received telegram) are always sent. Parameter data exchange may,
however, be blocked if bus bandwidth or PLC memory space is at a premium. The
data structure, and thus the PPO type, is normally specified by the bus master. If
no PPO type is specified (e.g. if a combined PROFIBUS DP/PROFIBUS FMS bus
master is used), the default PPO type is type 1 (parameter data exchange
enabled).
Process data from the serial link always has a higher priority than parameter data.
This means that a setpoint change or drive control change command will be
processed faster than a parameter change command.
Parameter write access over the serial link can be enabled or blocked as required.
Parameter read access is permanently enabled, allowing continuous read-out of
drive data, diagnostics, fault messages etc. A visualization system can thus be
realized with minimal effort.
Local control of the drive with the On, Off, Jog and Reverse buttons is possible at
all times in an identical fashion to when the module is not present.
PROFIBUS cables are connected to terminals within the Module. Cables are fed
into the module via cable glands.
Table 10-9 Maximum Cable Lengths for Data Transfer Rates
Data transfer rate
(Kbit/s)
Max. cable length of a
segment (m)
9,60
19,20
93,75
187,50
500,00
500,00
12000,00
1200
1200
1200
1000
400
200
100
The shield of the cable must be connected to the housing of the PROFIBUS
Module (i.e., recommended use of metal cable glands for this purpose).
A segment can be extended by using RS485 repeaters.
Recommendation: SINEC L2 repeater RS485 (Order No: 6ES7972-0AA00-0XA0).
For reliable operation of the serial bus system, the cable must be terminated at
both ends using terminating resistors. Bus terminations with the MICROMASTER
411 PROFIBUS Module is achieved using the Bus Termination Switch (see above).
Additionally, for 12 MBd operation, no stub length from the main bus cable is
allowed.