Siemens MICROMASTER 420 - Page 71

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MICROMASTER 420 Reference Manual
Issue A1
63
Table 3-9 Assignment of the PROFIBUS SUB-D socket connector
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1 Not connected (NC)
2NC
3 Send- and receive line RS 485, two wire, positive
differential input/output B/P
4 Request to send (RTS)
6 5V isolated power supply for termination resistors
7NC
8 Send and receive line, RS 485, two wire negative
differential input/output A/N
9NC
Table 3-10 Maximum Cable Lengths for Data Transfer Rates
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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 SUB-D connector.
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. For operation at 12MBd, cables must be
terminated in connectors with a built-in damping network. Additionally, for 12 MBd
operation, no stub length from the main bus cable is allowed.
Suitable SINEC-L2 DP connectors and cable for reliable operation up to 12 MBd
are listed below in Table 2-13:
Table 3-11 Order Numbers for Connectors and Cables
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6ES7 972-0BB10-0XA0 Bus Connector with PG interface
6ES7 972-0BA10-0XA0 Bus connector without PG interface
6XV1830-0AH10 Bus cable 20m-1000m
A floppy disk is supplied with the PROFIBUS module containing the handbook and
2 data files for configuring the relevant PLC system.