Festo Контроллеры двигателя SFC-LAC - Manual (Page 67)

3. Installation
3−17
Festo P.BE−GDCP−SFC−LACI−PB−E N en 0812NH
3.7 Connecting the field bus
3.7.1 Field bus cable
Note
Faulty installations or high transmission rates may cause
data transmission errors as a result of signal reflections
and attenuations.
Transmission errors can be caused by:
Ĉ missing or incorrect terminating resistor
Ĉ incorrect screened connection.
Ĉ branches
Ĉ transmission over long distances.
Ĉ unsuitable cables.
Observe the cable specifications. Refer to the manual for
your control system for information on the type of cable to
be used.
Note
If the SFC−LACI is installed in a machine on a movable
mounting, the field bus cable must be provided with strain
relief on the moving part of the machine. Please also
observe the relevant regulations in ENĂ60204 part 1.
Use a twisted screened 2−core cable for the field bus in
accordance with PROFIBUS specifications (EN 50170,
cableĂtype A):
Surge impedance: 135 ... 165 ġ (3 ... 20 MHz)
Capacitance per unit length: < 30 nF/km
Loop resistance: < 110 ġ/km
Core diameter: > 0.64 mm
Wire cross section: > 0.34 mm 2