Endress+Hauser iTEMP TMT85, Руководство по эксплуатации

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iTEMP TMT85 Electrical connection
Hauser 19
Maximum overall cable length
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 spurs (>1 m/3.28 ft). Please note the following:
• The maximum permissible overall cable length depends on the cable type used.
• Type A: 1900 m (6200 ft)
• Type B: 1200 m (4000 ft)
• If repeaters are used, the maximum permissible cable length is doubled. A maximum of
three repeaters are permitted between user and master.
Maximum spur length
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 (3.28 ft)):
Number of spurs 1 to 12 13 to 14 15 to 18 19 to 24 25 to 32
Max. length per spur 120 m (393 ft) 90 m (295 ft) 60 m (196 ft) 30 m (98 ft) 1 m (3.28 ft)
Number of field devices
In accordance with IEC 61158-2 (MBP), a maximum of 32 field devices can be connected
per fieldbus segment. However, this number is limited under certain conditions (explosion
protection, bus power option, field device current consumption). A maximum of four field
devices can be connected to a spur.
Shielding and grounding
The specifications of the Fieldbus Foundation provided in the "Wiring and Installation"
document must be observed during installation.
Bus termination
The start and end of each fieldbus segment must always be terminated by 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. Please also
note the following:
• 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.
Further information
General information and further details about wiring can be found on the website
(www.fieldbus.org) of the Fieldbus Foundation or in the Operating Instructions
"FOUNDATION Fieldbus TM Overview", available at: → www.endress.de → Download).
5.2.3 Fieldbus connection
Devices can be connected to the fieldbus in two ways: