Executive Summary
Occasionally, the on-site equipment may have
problems during production.EtherCATIn
the case of a complete network initialization failure, a power cycle or
reactivation of the configuration is required to recover. How can you diagnose
which slave has caused the network crash and what the possible causes are? This
article describes:
1.
EtherCATReason
for automatic return of Init by the master station and parameter settings
2.
View the number of times the slave
connection is lost
3.
Possible reasons for losing
connection from the station
Keywords:
EtherCATInit of the main station, continuous frame loss,
network interruption
Historical Versions
This article references the existing technical
document "EtherCATTroubleshooting method for network interruption caused
by continuous frame loss.docx", and added some content to the body to
enable users to read as much information as possible in one document. The
methods described in the article were guided by ETG technical experts, and are
hereby collated and released for user engineers to collect and forward.
Text
1 EtherCATReason
for the master station returning Init
Yes, hereTwinCATIn the settings, there is only one
possibility that the master station will enter Init by itself - the data packet
sent out cannot be returned for 10 consecutive times. According toTwinCATThe
default configuration of the master station will cause the master station to
enter Init and no longer attempt to re-enter OP. Restarting or activating the
configuration is required to re-enter OP. If this is the cause, it is usuallyTwinCATThe
log of shows the message that packet loss occurred 10 times.
1.1
The main stationReInitSettings.
Note: This setting is for security purposes, as in the event
that the outgoing data packet cannot be returned, the master station cannot
determine whether the data output to all slave stations has actually been
accepted, nor can it receive any data sent by the slave stations. In this
situation, it is safer to enter Init manually, wait for human intervention,
troubleshoot the issue, and then restart. Only cancel the master station for
troubleshooting purposes.ReInitThis option allows the master station to
maintain the OP status and continue to send data packets even if the data
packets cannot be retrieved. However, this has potential risks, so it is not
recommended for normal production. By the way, some third-party master stations
do not report this error, which may not necessarily be because their master
stations are more stable, but may be because they do not have this protection
function.
1.2 From the stationReInitSettings.
If a flash interrupt occurs in an individual slave station, resulting in
the failure of data packets to return, and the master station continues to send
data packets later, if the slave station reconnects, whether it recovers
communication depends on the slave station'sReInitSettings:
The default is also checked. If you cancel, even if the
master station sends data again, the slave station will not resume. This of
course allows you to immediately find out which slave station caused the packet
loss. In order to make the system stronger and overcome short-term (such as
less than 10 times) interruptions, it is usually recommended to use the default
configuration, which reinitializes the OP communication automatically after the
failure point is restored. 2 How to view which slave station has been
disconnected
There are two ways to check which slave station has
interrupted the connection: one is toEtherCAT The Online interface uses a PLC
program to read the Register of the slave station.
2.1 InEtherCAT Online interface displays the number
of times the slave connection is lost
EtherCATFrom the station, it can automatically record the number of
connection losses for each port. In the Online View of the master station,
select 0310 'Link Lost A/B'. Because the servo, stepper, or EL module only has
AB ports, the low byte of 0310 indicates the number of connection losses for
Port A, the entrance, and the high byte indicates the number of connection
losses for Port B, the exit.Port BThat is, the number of exports.
Then you can see
the value of Reg:0310 on the Online page:
The current value of Reg:0310 for address 1008 Term9(EK1100) in the above
image is 5, which is due to 5 times of plugging and unplugging the network
cable during testing. There are also several points to note:
(1) Unplugging the network cable only
affects the slave port A
If you unplug the network cable from the EK1100,
only the low byte of 0310 of the EK1100 itself will be incremented, while the
subsequent EL modules display normally. If you unplug the network cable from
the EK1110 connected to it, it will still display as if the low byte of 0310 of
the EK1100 was incremented, while the unplugged EK1110 displays normally.
(2) The Reg word from the station is
only reset when power is lost
The test results on the CX5130+TC3 platform
show that the EK1100 slave station power-down restart does not cause the value
to increase, as the value is reset each time the power is turned off. However,
the TC3 master station restarts or the TC3 development environment is closed
and then reopened, the Reg:0310 value remains unchanged.
(3) Diagnostic data can be exported as
a .csv file
Although direct screenshots can also be
analyzed, if there are many websites, multiple screenshots are needed.EtherCAT
The Online interface provides an export function. Select Export List from the
right-click menu in the image above to export diagnostic information to a .csv
file. Open the .csv file in Excel, and then select "Split Column"
under the "Data" main menu in Excel. Set the delimiter to
"semicolon", and then you can see the data for each column:
2.2 UseFB_EcPhysicalReadCmdRead it
If there is no engineer on site
to check with a computerEtherCAT OnlineInterface, which can be used to write
PLC programs to call function blocksFB_EcPhysicalReadCmdTo read the Register of
the slave station, for example:
Because the registered word cannot be configured toProcess
Data, so you can only read it using FB. Don't read it every cycle, as it will
consume too much CPU andEtherCATResources, suggestions inWcStateWhen it is
invalid, trigger the read instruction. If the number of slave stations exceeds
a certain limit, it is best to read in groups.
2.3 Watch the Run light from the station
If there is a slave station with data communication, the
connection light and running light will be on. However, if there is no data
communication, the Run light will not be on. However, this method is difficult
to check one by one if the electrical cabinets are scattered on site. Moreover,
if the master station stops communicating after 10 packet losses, or the
problematic slave station recovers communication within 10 times, then the
human operator will hardly see the change in the indicator light. If the
master/slave stations are not set to automaticallyReInitThe problematic slave
indicator will be different from other normal slaves.
3 WhyEtherCATConnection
will be lost
Possible reasons include: EMC interference, network cable
quality issues, virtual connection of network ports, loose network interfaces,
poor contact of slip rings, and self-damage of slave modules. The most common
are network cable quality and network port connection issues, which should be
investigated first.
3.1 Network cable quality
If it is a prefabricated network cable, it is usually
produced in bulk by a machine, and the quality of the crimping will be more
stable. If it is handmade, there are variables such as the length of the
reserved wire, the force used, and the contact between the shielding layer and
the metal sheet. You can try opening several connectors and inspecting them.
3.2 Network port connection
You can try to gently shake the
network cable of a station with your hand while monitoringEtherCAT Online,
check whether there is an increase in Lost Frame. If there is an increase, it
indicates that vibration during the machine's production process may have
caused packet loss. If it is determined that this node is the cause of the
failure, it is necessary to check the RJ45 connectors, RJ45 network ports for
looseness, damage, corrosion, etc. If conditions permit, the simplest solution
is, of course, to replace the components.