Siemens SIMATIC NET PROFIBUS manual Expansion, Total Cable, Tap Line

Topologies of SIMATIC NET PROFIBUS Networks

PROFIBUS-PA

DP/PA coupler Ex [i]
6ES7 157-0AD00-0XA0	Imax	I1	I2	I3...	...In
Protection EEx [ia] II C
Imax x 90 mA
DP/PA coupler Ex [i]		Field device	Field device	Field device		Field device
6ES7 157-0AD80-0XA0
	24 V DC	1	2		3...	...n
Protection EEx [ib] II C
Imax x 110 mA	PROFIBUS-DP		Explosion-protected area

PROFIBUS-PA

DP/PA coupler

6ES7 157-0ACx0-0XA0

ImaxI1

Imax x 400 mA

I2

I3...

...Im

	Field device	Field device	Field device Field device
24 V DC	1	2	3...	...m

PROFIBUS-DP

Figure 2-12 Field Device Power Supply in the Hazardous and Non-Hazardous Area

Expansion

If the maximum output current of the DP/PA coupler is exceeded, you must include a further DP/PA coupler.

Total Cable

The total cable is the total of the main cable and all the tap lines.

When using a standard PROFIBUS-PA cable with a cross-sectional area of

0.8mm2, the maximum length of the total cable (with a maximum number of field devices and worst-case positioning at the end of the cable) is as follows:

S560 m for DP/PA coupler (6ES7 157-0AC00-0XA0)

S680 m for DP/PA coupler (6ES7 157-0AD80-0XA0)

S790 m for DP/PA coupler Ex [i] (6ES7 157-0AD00-0XA0)

Tap Line

The maximum permitted tap line lengths are listed in Table 2-2. You should also remember the maximum length of the total cable (see above).

2-18	PROFIBUS Networks SIMATIC NET
	6GK1970-5CA20-0AA1 Release 2 05/2000