FMC Corporation - Talstar 80 사용자 설명서

Proline Promass 80 PROFIBUS PA

Wiring

27

The maximum network expansion depends on the type of protection and the cable specifications. 
The overall cable length combines the length of the main cable and the length of all the spurs 
(>1 m (>3 ft)).

Note the following points:
• The maximum permissible overall cable length depends on the cable type used:

• If repeaters are used, the maximum permissible cable length is doubled.

A maximum of three repeaters are permitted between user and master.

The line between the distribution box and field device is described as a spur.
In the case of non-Ex applications, the max. length of a spur depends on the number of spurs 
(>1 m) (>3 ft):

In systems that meet FISCO with EEx ia type of protection, the line length is limited to 
max. 1000 m (3280 ft). A maximum of 32 users per segment in non-Ex areas or a maximum of 
10 users in an Ex-area (EEx ia IIC) is possible. The actual number of users must be determined 
during configuration.

The start and end of each fieldbus segment are always to be terminated with a bus terminator. With 
various junction boxes (non-Ex), the bus termination can be activated via a switch. If this is not the 
case, a separate bus terminator must be installed.

Note the following points:
• In the case of a branched bus segment, the device furthest from the segment coupler represents 

the end of the bus.

• If the fieldbus is extended with a repeater then the extension must also be terminated at both 

ends.

General information and further notes regarding the wiring are contained in BA034S/04: 
"Guidelines for planning and commissioning, PROFIBUS DP/PA, field communication."

1900 m

6200 ft

1200 m

4000 ft

[m]

120 90  60

30

1

[ft]

400 300 200

100

3