PUB00147_DeviceNet_Plant_Floor_Troubleshooting_Guide

PUB00147_DeviceNet_Plant_Floor_Troubleshooting_Guide
Plant Floor Troubleshooting Guide
PUB00147R0
March 21, 2006
2006 © Open DeviceNet Vendor Association, Inc.
The Open DeviceNet Vendor Association (ODVA) Automotive Special Interest Group (SIG) is
pleased to offer this document as a tool for troubleshooting devices that have been
implemented into a DeviceNet network as well as the DeviceNet network itself.
The following individuals have been invaluable in putting this document together:
Training Committee Members:
Matt Kuzel
Borisa Begic
James O’Laughlin
Erick Rudaitis
Michael Giroux
Huron Networks
InterlinkBT
SICK, Incorporated
SMC Corporation of America
WAGO Corporation
Automotive SIG Members:
Erick Rudaitis, Chairperson
Marie Sandor, Administration
SMC Corporation of America
SMC Corporation of America
Thomas Dwyer
Greg Irwin
Gil Jones
Frank Latino
Matt Kuzel
Borisa Begic
Gary Workman
Enrico DeCarolis
Anton Suarez
Dave VanGompel
James O’Laughlin
Ed Ingraham
Mike Johnson
Michael Giroux
Chuck Sammut
Bosch Rexroth
DaimlerChrysler
EATON Corporation
Festo
Huron Networks
InterlinkBT LLC
General Motors
Numatics, Inc.
OMRON Corporation
Rockwell Automation
SICK, Incorporated
Siemens
SOLA / Hevi Duty
WAGO Corporation
Woodhead
For more information regarding the ODVA, including the Automotive SIG, please refer to the
ODVA website at:
www.odva.org
Plant Floor Troubleshooting Guide
DeviceNet Plant Floor Troubleshooting
Flowchart
See
Page 1
(Suspected Network Error / Multi-Node Problem)
DeviceNet Plant Floor Troubleshooting
Flowchart
See
Page 11
(Intermittent Failures)
DeviceNet Plant Floor Troubleshooting
Flowchart
See
Page 15
(Single Node Problem)
Walking the Network
See
Page 19
Segmenting the Network to Troubleshoot
See
Page 20
DeviceNet Network Checklist
See
Page 21
Start 1: DeviceNet Plant Floor Troubleshooting Flowchart
(Suspected Network Error / Multi-Node Problem)
Are the DeviceNet
scanner LEDs red
(Bus off)?
Note any
diagnostic
information on
DeviceNet scanner
if available.
No
Yes
Turn Auxiliary and DeviceNet Power
OFF, Wait 10 seconds, Turn back ON.
Examine scanner LEDs
Are the DeviceNet
scanner LEDs red
(Bus off)?
No
Yes
Cycle System, Auxiliary and
DeviceNet Power, Wait 10 seconds
Examine scanner LEDs
Are the DeviceNet
scanner LEDs red
(Bus off)?
No
Yes
See
Page 19
Review Walk the Network
Attach DeviceNet Diagnostic Tool
Go to
B
Go to
O
See
Page 2
See
Page 11
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 1
B
Was problem
found during the
network walk?
Yes
Done
No
Is there only one node
with red Module (MS)
or Network Status
(NS) LEDs?
Yes
Go to
E
No
See
Page 4
Disconnect DeviceNet trunk cable from the
cabinet with scanner module.
Attach terminating resistor. Turn off
DeviceNet power, wait 10 seconds, turn
DeviceNet power back on.
Are the DeviceNet
scanner LEDs red
(Bus off)?
The bus off indication
should be gone and
diagnostics for
missing nodes should
be displayed.
Yes
Check nodes and cabling inside
cabinet.
No
Reconnect network.
Problem fixed?
Are there multiple
DeviceNet network
power supplies?
Yes
No
No
Yes
Disconnect supplemental power
supplies.
Go to
C
See
Page 3
DeviceNet Plant Floor Troubleshooting Guide
Go to
F
Go to
D
See
Page 5
See
Page 3
PUB00147R0
Done
Page 2
C
Is V- of the power
supplies tied to V- of
DeviceNet?
Yes
Is V+ of the power
supplies wired
separately?
No
Yes
No
Wire V- of all power supplies together.
Reconnect trunk cable.
Wire V+ of all power supplies
separately.
Reconnect trunk cable.
Go to
F
See
Page 5
Start
D
Are the nodes and
cables okay?
Yes
No
Replace cable or node.
Replace scanner.
Reconnect network.
Reconnect network.
Go To
Start 1
Go to
Start 1
See
Page 1
See
Page 1
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 3
E
Disconnect node from network.
Turn Auxiliary and DeviceNet Power
OFF, Wait 10 seconds, Turn back ON.
Are the DeviceNet
scanner LEDs red
(Bus off)?
Note: Other nodes can
cause a node to go offline.
No
Yes
Replace node.
Verify Baud Rate, Node Address and
.EDS file information.
Replace drop cable.
Are the DeviceNet
scanner LEDs red
(Bus off)?
No
Done
Yes
Go to
F
See
Page 5
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 4
F
Note:
Changes such as cabling,
tools, firmware, nodes, etc.
Have any changes
been made to network
since last time worked
consistently?
Yes
Investigate changes
No
See
Page 23
Check Voltages
See Items 12, 13 & 14 in
DeviceNet Network Checklist
Go to
Start 1
See
Page 1
Are DeviceNet
voltages correct?
Yes
Go to
K
No
See
Page 8
Change power supply
Go to
G
See
Page 6
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 5
G
Bus off condition
fixed?
Yes
Done
No
See
Page 21
Complete
DeviceNet Network
Checklist
Errors found and
fixed?
Note: This will now take
some time. Check
1. Cables, 2. Node,
3. Segment, 4. Grounding
5. CAN transceiver shorted
6. Not 60Ω etc.
Yes
Done
No
See
Page 23
Check Voltages
See Items 12, 13 & 14 in
DeviceNet Network Checklist
Voltages OK?
Yes
Go to
I
No
See
Page 7
Go To
H
See
Page 7
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 6
H
All cable
connections OK?
No
Fix cable connection
Yes
I
Go to
Start 1
See
Page 1
Attach DeviceNet diagnostic tool and
measure CAN errors
> 20
errors/second?
No
Go to
K
Yes
See
Page 21
See
Page 8
Recheck for ground loops
using
DeviceNet Network Checklist
Problem found and
fixed?
Yes
Done
No
Go to
J
See
Page 8
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 7
J
Replace power supply again in the
case that current power supply is also
bad.
Errors found and
fixed?
Yes
Done
No
K
Divide network into two sections.
Connect section 1 and move
terminating resistor.
Network up?
No
Yes
Disconnect Section 1. Connect
Section 2 and move terminating
resistor.
Network up?
Troubleshoot other
½ of the network
No
Isolate problem
Go to
M
Yes
Go to
L
See
Page 9
See Page 9
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 8
L
Checking for
potential network
load issues.
Replace scanner. Reconnect entire
network.
Bus off condition
fixed?
Yes
Done
No
Check for wiring
and other nodes
within the scanner
cabinet.
Isolate problem
Check for issues in cabinet
Problem
Solved
Yes
No
M
Rewalk network looking for stressed
cables (e.g. bend radius too tight, tie
wrapped where it causes failure)
Any shorts or
opens?
No
Go to
N
See Page 10
DeviceNet Plant Floor Troubleshooting Guide
Yes
Fix problem
Go to
Start 1
See
Page 1
PUB00147R0
Page 9
N
Disconnect all nodes, add one node at
a time until network communication
fails. Determine node that causes bus
off and replace
Still bus off?
No
Done
Yes
GET HELP
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 10
Start 2:
DeviceNet Plant Floor Troubleshooting Flowchart
(Intermittent Failures)
Do you have a
DeviceNet
diagnostic tool?
No
Yes
O
Connect tool to diagnose bus.
(Monitor voltages, CAN frame errors,
etc.)
Problem
diagnosed?
No
Yes
Fix problem indicated
Problem fixed?
No
Yes
Go to
P
Done
See
Page 12
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 11
P
Does problem
occur with noise
(from external
device or event)?
VFD load dumps, Servos
enabled, Welding, Other
Maintenance in the Area
(External to Network), etc.
No
Yes
Go to
R
Check noisy device’s grounding
See
Page 14
Is the device’s
grounding correct?
Yes
No
Grounding problem
Fix grounding
Problem fixed?
No
Yes
Done
Go to
Q
See
Page 13
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 12
Q
Is there a noisy
device on
DeviceNet?
Go to
R
Yes
See
Page 14
Replace DeviceNet interface card on
that device
Problem fixed?
e.g. VFD, Welding,
Robot, Motor etc.
No
No
Yes
Done
DeviceNet Plant Floor Troubleshooting Guide
Call Manufacturer
PUB00147R0
Page 13
R
Check DeviceNet grounds
(missing grounds or ground loops).
Grounds OK?
Yes
No
Fix grounds.
Problem fixed?
No
Yes
Done
Go to
F
See
Page 5
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 14
Start 3: DeviceNet Plant Floor Troubleshooting Flowchart
(Node Problem)
If this is your third time through this process, consider the possibility that this is a network issue rather than a node issue.
Turn Auxiliary and DeviceNet Power
OFF, Wait 10 seconds, Turn back ON.
Verify scanner is functioning.
Is the Device’s
Network Status LED
flashing or solid green?
Is the Device’s
Network Status
LED solid green?
Yes
No
Go to
V
See
Page 17
No
Yes
Unplug device and check DeviceNet
power and Auxiliary power at the node
Voltages OK?
Done
No
Find and fix voltage problem
Yes
Is the device’s
Network Status
LED on solid red?
No
Go to
Start 3
See
Above
Yes
Go to
S
Go to
V
See
Page 16
See
Page 17
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 15
S
Verify node address and data rate. If no
changes required, replace node. Be sure
that node address, data rate and .EDS
revision are correct.
Is the device’s Net
Status LED on
solid red?
No
Go to
Start 3
Yes
See
Page 15
Unplug node
Connect DeviceNet diagnostic tool
Can you see other
nodes on the
network?
Possible cable, tee
or other node that
is causing the
problem
No
Replace drop cable or tee
Yes
Disconnect DeviceNet diagnostic tool
reconnect node. Disconnect adjacent
nodes. Turn Auxiliary and DeviceNet
Power OFF, Wait 10 seconds, Turn
back ON.
Go to
Start 3
See
Page 15
Is the device’s
Network Status LED
on solid green?
No
Yes
Go to
T
Go to
U
See
Page 17
See
Page 17
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 16
T
U
One of the adjacent nodes may be
causing the problem. Replace bad
node. Reconnect nodes one at a time
to confirm which node is causing the
problem.
Disconnect nodes until the device’s
Net Status LED is on solid green.
Reset power after removal of each
node to determine if problem has
been corrected.
Go to
Start 3
See
Page 15
Reconnect nodes one at a time to
confirm which node is causing the
problem.
Replace offending node.
If the node’s Net
Status LED is
flashing green, it is
ready to establish
communication.
V
Go to
Start 3
See
Page 15
Check HMI or scanner for diagnostic
information for corrective action.
Was corrective
action successful?
Yes
Done
No
Walk the network and check
connections.
Go to
W
See Page 18
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 17
W
Problem found and
fixed?
Yes
No
Replace node
Node online?
Yes
No
Replace drop cable or tee
Node online?
Yes
Done
No
Go to
U
See
Page 17
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 18
“Walking” the Network
Here are the things to keep in mind and look for when walking a network.
First try to look at a drawing or layout of the network so you know where the cables go and if the
lengths are correct. Sometimes this is not possible but look around in the controller cabinet for
this information. Also remember that Auxiliary Power topology and implementation is just as
important as DeviceNet topology and implementation. Check both when walking the network (I.e.
for additional information, see Auxiliary Power – Section 14 in the DeviceNet Network Checklist).
•
•
•
Loose connections are the number one cause of failures.
-
Make sure all connections are undamaged.
-
Connections may look good but not be tight. Check them.
Cable stress is the second thing to look for.
-
Cable radii might be too tight or stressed with tie wraps. There is a lot of vibration in a
plant and if the cables are stressed it will create a failure point.
-
Some cable trays are mounted on long fence post and the cables brought down from
them. At the point where they leave the cable tray and bend down could be a potential
spot for failure.
Grounds are very important!
- Visually inspect grounding to assure that grounding location is clean and connection is
tight. Make sure that all components are properly grounded.
•
Separate high voltage cables from DeviceNet cables!
-
Power, welding or servo cables are sometimes put on top of the DeviceNet cables or put
in the same cable trays. DeviceNet cables must have the proper distance between these
cables.
-
To clean up the wiring power, servo, or welding cables are tie wrapped together.
DeviceNet cables must have the proper distance between these cables.
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 19
Segmenting a network to troubleshoot a problem.
Finding a network cable problem is sometimes not the easiest thing to detect. The following
step-by-step process will assist in locating cabling issues:
•
Divide the network into two halves to determine which half is causing the trouble by
physically disconnecting the trunk cable and placing the terminating resistor at the break
point
•
Once you determine the half causing the trouble you can approach the problem two ways.
− Continue to divide the defective portion of the network in half to further isolate the
trouble; or
− Re-walk the network making sure that all connections are still “OK” .If everything looks
“OK” then start at the controller and go to the first drop. Break the trunk cable and
insert a terminator. Walk the terminator down the trunk until the network fails.
Once the problem location has been determined, consider the following cable connection /
details as possible causes of the problem:
−
−
−
−
Tee Connection
Drop Connection
Node Connection
Loading problem with a node or insufficient bus power. (A volt-amp-meter should be
used to determine if the problem is related to bus loading).
If the network has been running and then fails, it is often due to a bad cable or “Tee” connection.
Remember: There could be one or more causes for a specific problem. Take your time and
check thoroughly to minimize the possibility of missing something.
DeviceNet Plant Floor Troubleshooting Guide
PUB00147R0
Page 20
Cell Number :
Tool Number :
Percent Complete:
Station Number :
DeviceNet Network Checklist
The following items should be completed during the implementation of DeviceNet networks commissioning. This will act as a record of the values
attained after installation of a working network and can be used for comparison for any future network / device troubleshooting.
ID
Item Description
Checked
Date
Comments
Physical Inspection
1
Are all DeviceNet devices approved for use on the project?
Make sure that DeviceNet taps are of the proper type.
___/___/___
2
Are 24VDC Power Supply calculations supplied? If the
network uses more than one supply, is the network connected
as designed?
___/___/___
Are all the trunk and drop cables separated from high voltage
and potential noise sources in accordance with the ODVA
DeviceNet Planning and Installation Guide?
___/___/___
Are all DeviceNet Drop & Trunk line cables routed without
strain on the connection points due to bending or tension?
Are all connections tight?
___/___/___
3
4
5a
Are the drop cables less than or equal to 20 feet (6 meters)?
___/___/___
5b
Is the sum of all drop lines less than the maximum allowed for
the network data rate DeviceNet specification?
___/___/___
6a
Is the trunk line less than the maximum length allowed for the
network data rate in the DeviceNet specification?
___/___/___
6b
Are both terminating resistors in place at the ends of the trunk
line?
___/___/___
7
Are all selectable DIP switch / rotary switch settings (node
address & baud rate) correct?
___/___/___
8
Is the DeviceNet 24VDC power supply (V-) bonded directly to
the ground buss bar (#12 wire) at one location only?
___/___/___
9
Are there any frayed or exposed wires on open style
connectors creating a possible shorted condition?
___/___/___
If the DeviceNet network uses more than one power supply,
are the V- connections of all power supplies tied together and
V- only bonded to the ground buss at one location?
___/___/___
10
Note regarding all Electrical Tests that follow:
Always keep the same reference point when making measurements. This allows you to trace wiring problems and find grounding problems. If you put
the black lead on the Earth ground point, make sure you always use the same point and the same lead. When performing any resistance check, you
cannot have less than “0” Ohms. A negative resistance value indicates you may have voltage on the ground, or on the wire you are checking. Remove
the source of any voltage to get an accurate measurement.
Design Source ___________________________________
Controls Engineer
______________________________
Design Engineer _________________________________
Date
______________________________
DeviceNet Plant Floor Troubleshooting Guide – DeviceNet Check List
PUB00147R0
Page 21
Cell Number :
Tool Number :
ID
11
Percent Complete:
Station Number :
Item Description
Checked
Date
Comments
Network Termination Test
1.
2.
3.
4.
Follow shutdown procedures (if any)
Stop all network communication.
Turn all network and auxiliary power supplies off.
Measure and record the DC resistance between CANH
and CANL at the middle and ends of the network.
If the measured value is <50 ohms
Check for short circuit between CANH and CANL
wiring
Check for more than two terminating resistors
Check nodes for faulty transceivers
If the measured value is 50-70 ohms
Normal (Do nothing)
___/___/___
If the measured value is 71-125 ohms
Check for open circuits in CANH or CANL wiring
Check for one missing terminating resistor
If the measured value is > 125 ohms
Add terminating resistor
Check for open circuits in CANH and CANL wiring
Design Source ___________________________________
Controls Engineer
______________________________
Design Engineer _________________________________
Date
______________________________
DeviceNet Plant Floor Troubleshooting Guide – DeviceNet Check List
PUB00147R0
Page 22
Cell Number :
Tool Number :
ID
Percent Complete:
Station Number :
Item Description
12
Checked
Date
Comments
Network Power Supply Ground Test
1.
Turn all network power supplies off. Disconnect the Vand Shield wires from ground and from each other.
2.
Using a Digital Voltmeter, measure DC voltage from
shield to ground at all power supplies. Is there less
1
than 1VDC?
3.
Remove all sources of voltage before continuing.
4.
Measure and record the DC resistance between Vand earth ground.
Measured value should show infinite resistance. If
other value is measured, look for swapped V- and
shield wires at termination points.
5.
Measure and record the DC resistance between Shield
and earth ground.
Measured values greater than 20kΩ are considered
Normal. For measured values that are greater than
1 kΩ and less than 20 kΩ:
-
Disconnect both DeviceNet connectors on the top
of the main control panel and repeat the above
procedure. If the problem remains, check
connections in the main control panel. Look for
swapped V- and shield wires at termination
points.
-
If the problem went away, segment the network
and isolate the location of the problem, and
check for grounded V- or Shield wires.
Sometimes the V- and Shield connections are
transposed, which would cause ground loops.
6.
Reconnect the V- and Shield wires to ground.
7.
Go to each end of the network and remove terminator.
Check resistance between V- and Shield to verify that
there is not a broken shield wire. DC Resistance
1
should be < 20Ω.
___/___/___
For measured values greater than 20Ω, check for
broken shield
1
Does not apply to applications in which flat cable is utilized for DeviceNet Communication.
Design Source ___________________________________
Controls Engineer
______________________________
Design Engineer _________________________________
Date
______________________________
DeviceNet Plant Floor Troubleshooting Guide – DeviceNet Check List
PUB00147R0
Page 23
Cell Number :
Tool Number :
ID
13
Percent Complete:
Station Number :
Item Description
Checked
Date
Comments
Network Power Supply Common Mode Voltage Test
1.
Turn all network power supplies on.
2.
Configure all nodes for their maximum current draw
from network power. Turn on outputs that use network
power.
3.
Measure and record the DC voltage between V+ and
V- where each power supply connects to the trunk.
4.
Measure and record the DC voltage between V+ and
V- at the ends of the network.
Measured values between 11.0 VDC and 25.0 VDC
are consistent with the DeviceNet Specification for
proper DeviceNet communication.
However, input devices that may rely V+ and V- for
power may not operate properly at voltages less than
20 VDC. Check input device (e.g. proximity sensors,
photoelectric sensors, etc.) to verify device is within
voltage specifications.
5.
Measure between V- and Shield. Measured values
less than 4.6 VDC are considered normal.
___/___/___
If measured value from:
Item 4. Is < 11.0 VDC; or
Item 5. Is > 4.6 VDC,
The network may not operate properly.
Possible solutions are :
- Shorten the overall length of the network cable.
- Move the power supply in the direction of the
overloaded section.
- Move nodes from the overload section to less loaded
section.
- Move high current loads close to the power supply.
- Break the network into two separate networks.
- Add power supply.
Design Source ___________________________________
Controls Engineer
______________________________
Design Engineer _________________________________
Date
______________________________
DeviceNet Plant Floor Troubleshooting Guide – DeviceNet Check List
PUB00147R0
Page 24
Cell Number :
Tool Number :
ID
14
Percent Complete:
Station Number :
Item Description
Checked
Date
Comments
Auxiliary Power Measurements
1.
Monitor the voltage present at both ends of the
auxiliary power trunk cable under normal operating
conditions and record the high and low values
observed. The use of an oscilloscope may be
necessary.
2.
Check all manufacturers’ specifications to verify that
the auxiliary power observed falls within the
manufacturers’ specifications.
___/___/___
If problems are observed, consider the following
- Add an additional power supply
- Shorten auxiliary power trunk line cabling
- Check for influence of noise
- Assure that the grounding requirements outlined
in the manufacturers’ specifications have been
met.
Design Source ___________________________________
Controls Engineer
______________________________
Design Engineer _________________________________
Date
______________________________
DeviceNet Plant Floor Troubleshooting Guide – DeviceNet Check List
PUB00147R0
Page 25
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement