Siemens S7-400 installation manual Lengths of Spur Lines

Networking

Lengths of Spur Lines

If you do not fit the bus cable directly at the bus connector (for example, when using a PROFIBUS-DP bus terminal), you must take into account the maximum possible spur line length.

The following table gives the maximum lengths of spur lines allowed per bus segment:

Table 5-3 Lengths of Spur Lines per Segment

Transmission Rate	Maximum	Number of Nodes per		Maximum
	Length of a	Spur Line Length of ...		Length of
	Spur Line			Spur Lines
		1.5 m and	3 m
				per Segment
		1.6 m
9.6 to 93.75 kbps	3 m	32	32	96 m
187.5 kbps	3 m	32	25	75 m
500 kbps	3 m	20	10	30 m
1.5 Mbps	3 m	6	3	10 m

A spur line is not permissible with transmission rates greater than 1.5 Mbps.

To connect a programming device or PC, use the connecting cable for the programming with theorder number 6ES7901-4BD00-0XA0. You can use several connecting cable with this order number for programming devices in one bus configuration.

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