Festo Электромотор MTR-DCI - Manual (Page 64)

3. Installation
3-16
Festo P.BE-MTR-DCI-PB-EN en 1209a
3.6.1 Fieldbus cable
Note
If installation has not been carried out correctly and if high
baud rates are used, data transmission errors may occur
as a result of signal reflections and attenuations.
Causes of the transmission faults may be:
– Missing or incorrect terminating resistor
– Incorrect screening/shield connection
– Branches
– Transmission over long distances
– Unsuitable cables
Observe the cable specifications. Refer to your controller
manual for information on the type of cable to be used.
Note
If the MTR-DCI is mounted onto a moving part of a ma-
chine, the fieldbus cable on the moving part must be pro-
vided with strain relief. Please observe also the relevant
regulations in EN 60204 part 1.
Use a twisted, screened 2-core cable for the fieldbus cable in
accordance with PROFIBUS specifications (EN 50170, cable
type A):
Surge impedance: 135-165 ohm (3-20 MHz)
Capacitance per unit length: < 30 nF/km
Loop resistance: < 110 Ohm/km
Core diameter: > 0.64 mm
Core cross-section: > 0.34 mm
2
Bus length Exact specifications on the bus length can be found in the
next section and in the manuals for your control system.