Transcript Parameterization - Iran University of Science and Technology

Bus Physics & Wiring
 PROFIBUS wiring/installation can be done with:
 Copper
 Fiber optic
 Infrared & RF components
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Bus Physics & Wiring
Date 09/06/00, Page 1
Bus Physics & Wiring
 PROFIBUS is based on RS485...
Network consists of
RS485 segments
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Proper
installation
required
Bus Physics & Wiring
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Bus Physics & Wiring
 PROFIBUS Segments
Connected via
repeaters
New segment when
maximum length or
number of devices per
segment is reached
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Bus Physics & Wiring
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Bus Physics & Wiring
 PROFIBUS Segments - Repeater
Segment 1
Segment 1
Isolation
Segment 2
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Bus Physics & Wiring
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Bus Physics & Wiring
 PROFIBUS - Segment & Network Length
12,000
10,000 10,000
10,000
10,000
10,000
8,000
Network [m]
Segment [m]
6,000
4,000
4,000
2,000
2,000
1,000
1,000
1,000
1,000
400
0
9.6
s
19.2
93.75
187.5
500
200
1,500
1,000
1,000
1,000
100
100
100
3,000
6,000
12,000
[kbaud]
Bus Physics & Wiring
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Bus Physics & Wiring
 PROFIBUS Segments - Nodes/Devices
 Up to 126 addressable nodes per network
 Up to 32 devices per segment
 What counts as “device”?
PROFIBUS
Nodes (e.g. I/O)
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Optical Link
Modules
(OLMs)
Repeater
Bus Physics & Wiring
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Bus Physics & Wiring
Up to 126
addressable
nodes per
network
Up to 32
devices per
segment
 PROFIBUS Segments - Example
Address #0
Address #31
Address #30
Address #60
No Address
Address #120
Address #90
Address #91
Address #61
No Address
No Address
Address #121
No Address
Address #125
= Repeater
= OLM
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation
Drop Lines
Cable
Distances
Shielding &
Grounding
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Termination
Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - Shielding & Grounding
 Improves EMC behavior
 Provides a low impedance (short) return path for noise and
current
 Reduces the emission from the bus
!!!
Shield is not always connected to
protective GND within the devices;
therefore, make sure the cable shield
will be connected to GND before it
enters or leaves the cabinet
!!!
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - Cable Distances
>= 20 cm
Cable
Category
I
>= 10 cm
Cable
Category
II
>= 10 cm
Cable
Category
III
>= 50 cm
>= 50 cm
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Cable
Category
IV
>= 50 cm
Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - Cable... (continued)
 Category I:
 LAN cables (e.g. Ethernet)
 Other communication cables
 Category II:
 Shielded and unshielded cables for DC voltages > 60V and <= 400 V
 Shielded and unshielded cables for AC voltages > 25V and <= 400 V
 Category III:
 Shielded and unshielded cables for DC and AC voltages > 400 V
 Category IV:
 Signal cables of categories I - III at risk from direct lightning strikes,
e.g., connections between components in different buildings
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - T-Connections (Drop/Stub/Spur)
 Every branch or drop directly from the cable
 Stubs to devices cause reflections (additional capacitance)
 Repeaters are not spur-lines
Device
Device
RS485
RS485
Internal to device
Between device and
trunk line
(A)
(B)
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - T-Connections (Drop/Stub/Spur)
600
550
500
500
500
450
400
Allowed Length [m]
350
300
250
200
150
100
100
50
33
0
9.6
19.2
93.75
187.5
20
500
6.6
1,500
0
3,000
0
6,000
0
12,000
[kbaud]
Although stub lines can theoretically be tolerated at the
lower baud rates, the recommendation is to avoid the use
of stub lines altogether.
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - Termination
 Termination for each segment at BOTH ends
 Termination works ONLY when supplied with power
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Bus Physics & Wiring
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Bus Physics & Wiring
 Installation - Termination: Example
Repeater
OLM
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OLM
OLM
Bus Physics & Wiring
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Bus Physics & Wiring
 Wiring - Easy, when you use the right tools...
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Bus Physics & Wiring
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Bus Physics & Wiring
 Wiring - Easy, when you use the right tools...
1. How to hold the insulation
stripper in your right hand.
2. Match up the cable end with
the template so that your left
index finger is against the end
surface of the tool.
3. Insert the end of the cable into
the stripper using your left index
finger as a limit stop to ensure the
correct length is inserted.
4x
4. Clamp the cable firmly in
the stripper.
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5. Rotate the stripper around
the cable 4 times in the
direction of the arrow.
6. With the clamp still closed,
pull the stripper off the end of
the cable.
Bus Physics & Wiring
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Bus Physics & Wiring
 Wiring - Easy, when you use the right tools...
7. The removed insulation
remains in the stripper. After
releasing the clamp, the
remnants can be removed.
8. Pull the protective foil off the
cores.


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9. After removing the insulation
from the cores, the cable can
be fitted into the PB connector.
green wire A
red wire
B
Bus Physics & Wiring
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Bus Physics & Wiring
 Copper is not the End of the Road...
 Plastic, PCF and glass fiber optic available
 Plastic - 50m between 2 Optical Link Modules (OLM)
 PCF - 300m between 2 OLMs
 Glass - up to 15km between 2 OLMs
 Connections via modules or integrated interface
 When is Fiber Optic the Choice?
 Noise immunity & independence from potential
differences
 Cover longer distances
 Line, ring and star configuration possible
 Media redundancy
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Bus Physics & Wiring
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Bus Physics & Wiring
 Fiber Optic - Optical Link Modules (OLM)
PROFIBUS FO Glass, PCF or Plastic
OLM
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Bus Physics & Wiring
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Bus Physics & Wiring
 Fiber Optic - Integrated FO Interface
= Optical Bus Terminal (OBT)
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PROFIBUS FO PCF or Plastic
Bus Physics & Wiring
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Bus Physics & Wiring
 More Options... Infrared Components
 Wireless linking of devices (up to 15m)
 Communication with moving devices
 Communication with changing devices
 Noise immune
 Ground independent
 More Options... RF Technology
 http://www.micro-control.no
 http://www.akerstroms.no
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Bus Physics & Wiring
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