Table of Contents
Advertisement
Wiring
6.6.2
CANopen, PROFIBUS DP
Depending on the unit type, socket X42 is assigned to
A combined CANopen/PROFIBUS DP interface
}
Two CANopen interfaces
}
6.6.2.1
Wiring guidelines for the CANopen interface
The CAN network is designed in a linear structure.
The overall line length and the length of the stub lines depend on the transmission rate
}
and on the cable properties (cable resistance and cable capacitance).
The signal lines must be terminated with resistors on the first and last subscriber.
}
A characteristic impedance of 120 Ohm is acceptable for bus lengths up to 40 m.
}
Fig.: Overall length and length of the stub lines on a CAN network.
Legend:
Node: CANopen subscriber
}
a: Length of stub line
}
A: Branch
}
R
}
T
Relationship between transmission rate, bus length and length of stub lines:
Transmission rate
[kBit/s]
1000
500
250
The following table provides an approximate overview of the size of the terminating resistor
R
with different cable lengths. In each specific case, details of the characteristic imped-
T
ance can be found in the cable specification.
Operating instructions PMCprimo C
1002242-EN-03
Node 2
Node 1
R T [
W
]
: Terminating resistor
Bus length l [m]
10
70
115
Node 3
A
l
Length of stub line
a [m]
1.5
5.5
11
Node n-1
a
Node n
A
R T [
W
]
Overall length of all
stub lines [m]
7.5
27.5
55
30
Advertisement
Table of Contents
