Technical Insights Convergence of Automation and IT networking

Technical Insights
Nov, 2014
Convergence of Automation and IT networking management
with ProView Switches
In a modern industrial environment, sensors, control nodes, PLCs and SCADA servers are connected via
switches and wireless Apps, to create a complex network. As the number of devices increase,
management and issue diagnostics are a challenging job for both IT and automation professionals. As a
global leader of industrial networking, Advantech introduces the world’s very first series of switches that
will lead the convergence management in the worlds of IT and automation: The “ProView” series of
switches.
ProView switches combine the advantages of both managed and unmanaged switches to introduce a
simple and cost effective solution with information for central network management and diagnostics.
Figure 1. ProView Switch in an Industrial network
Technical Insights
Nov, 2014
In order to allow both automation software and IT software to monitor the switch status, the ProView
series switches support both Modbus/TCP and SNMP protocols. This allows SCADA software such as
Wonderware InTouch, Advantech WebAccess, WinCC, iFix, and IT Network Management System (NMS)
software such as SNMPc and OpenNMS to monitor the switch device status in real time.
The devices come with Port-based QoS for deterministic data transmission that allows data from the VIP
port to have a higher priority compared to data from a normal port.
ProView switches use the highest quality components, to achieve a wide range of operating
temperature from -40 to 75°C along with Level 3 EMS protection from electromagnetic interference.
System Highlight
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Communication with HMI / SCADA software via Modbus/TCP.
Communication with NMS (Networking management system) via SNMP.
Port-based QoS for deterministic data transmission.
Wide Operating temperature range from -40 to 70°C.
EMS level 3 protection for extreme outdoor environments.
Power saving with Energy Efficient Ethernet Standard, IEEE 802.3az.
Jumbo Frames up to maximum of 9,216 Byte.
Power source redundancy with two 12~48V DC power inputs and P-Fail relay.
Loop detection.
Communication with HMI/ SCADA software via Modbus/TCP
The Modbus/TCP protocol has been built into Advantech ProView switches which allow a majority of
popular SCADA system such as InTouch, InduSoft, WinCC and iFIX to obtain device status and
information. This allows all devices, including ProView switches and I/O control devices, to be controlled
and monitored through one HMI/SCADA system.
In the following SCADA software example, by using InTouch from Wonderware, we connect the SCADA
server (TPC-651H), one analog I/O Modbus TCP module (ADAM-6017) and one digital I/O Modbus TCP
module (ADA-6050) to the ProView switch (EKI-5526). The topology is shown below:
Technical Insights
Nov, 2014
Figure 2. Typical Industrial Application Topology
We use the SCADA software to access the memory address in the ProView Switch through Modbus/TCP.
This allows us to obtain the device information such as the device name, FW version, MAC and IP
address, and also the port status information such as port link up/down, link up counter and port speed.
This information further helps the engineer diagnose any issue. When a signal is lost by the end device,
by having both the network information and the device information displayed on the SCADA, we are
able to conclude that the signal lost is caused by either the network or the end device itself. For example,
in figures 2 and 3 below, by reading the status of port 4 at memory location 34100 on the ProView
switch through Modbus/TCP; we are able to know that the port has been disconnected and combined
with SCADA HMI, the status indicator of port 4 turns red. This allows on-site engineers to easily identify
that the lost signal is caused by a disconnected network cable or by malfunction of the voltmeter or the
Modbus TCP module. This helps to quickly narrow down the root cause of an issue.
Technical Insights
Nov, 2014
Figure 3. Switch device information, switch port status and I/O device reading in one SCADA system. The
red rectangle indicates that the port 4 has been disconnected.
Figure 4. Wonderware InTouch SCADA Port Information Sample using EKI-5726
Technical Insights
Nov, 2014
As well as basic device information and the port link up/down status, the ProView switch provides
detailed statistical port information on each port including speed, linkup counter, count on the multicast
packet, count on unicast packet and count on error. This allows engineers to observe the network status
and statistic in detail from any HMI / SCADA software which supports Modbus/ TCP. The detailed
information provided by the ProView switch is listed in the table below.
System Info
Vendor ID
Port Status
Port Status
Unit ID
Port Speed
Product Code
Flow Control
Vendor Name
Port Description
Product Name
Link Up Counter
FW Version
Tx Packets Counter
Ethernet MAC address
Rx Packets Counter
IP Address
Table 1: Modbus Information table
In a HMI / SCADA system such as InTouch, address mapping and Modbus/TCP connection is the initial
step to setup the InTouch.
Using ProView switch with Wonderware InTouch
For InTouch being able to connect to the ProView switch, we need to have the InTouch know where our
ProView switch is on the network. Thus, we first need to create a new node with an IP of the ProView
switch in the System Management Console.
Technical Insights
Nov, 2014
Figure 5. Create a node in the InTouch SCHADA
Then, we set the node with the correct parameters.
Figure 6. Config node with correct parameter.
Technical Insights
Nov, 2014
Next we add one device, “ProVewSW” in the device group with a suitable update interval time; in this
case we chose 1000 ms.
Figure 7. Add the device in device groups and set update interval.
After the connection setting is finished, right-click on the node and select “activate the server” to start
the server.
Another initial configuration is the tags. Tags have been used in InTouch as the points of data. Tags can
be defined and modified by using the Tagname dictionary.
InTouch needs tags, which are points of data and uses the Tagname dictionary to define these data
points. You can modify or create new tags using the Tagname dictionary.
Figure 8. Tagname Dictionary.
Technical Insights
Nov, 2014
In this example, we created a new tag to obtain the Ethernet port 1 status from the ProView switch. We
created “Port001_Status” as the tag name, and I/O Integer as the tag type. Refer to the Modbus TCP
address mapping table in the user manual, we know the port status data stored on the switch is
represented by four HEX characters, which is 65,536 bits in data length. Thus we entered Min EU and
Max EU from 0 to 65535. Then we selected the pre-configured device name “ProViewDemo” as the
access name. Finally, we referred to the Modbus TCP address mapping table that comes with user
manual, we can find the address for the Ethernet Port 01 status data is stored at memory location,
34097, thus we enter 34097 in the item field.
After the tag and connection have been setup correctly, the HMI/SCADA software is now able to obtain
the specific data from the ProView switch. With minor modification to the interface, you will be able to
display the data on the SCADA screen in the way you preferred. For example you can have the
connected port in green and disconnected port in red as in the example below. The SCADA will obtain
the information from the ProView switch and display the port status for all 16 Ethernet ports in real
time.
Figure 9. SCADA display interface example, port status for EKI-5526.
Communication with NMS software via SNMP
ProView switches support SNMP (Simple Network Management Protocol) which allows IT NMS
(Network Management System/Station) software such as SNMPc, SusuAccess NMS and OpenNMS to
perform device management including status monitoring, configuration and even events notification.
This allow IT engineers to have better monitoring and control on the network and easier
troubleshooting when something went wrong on the network.
Technical Insights
Nov, 2014
In an industrial environment such as manufacturing, nothing is more important than keeping the
network, which is formed by thousands of sensor devices, running smoothly without any downtime.
SNMP has been widely used by engineers to monitor the network device status and an NMS is able to
provide an intuitive network topology with a real time device status similar to the topology example
shown in Figure 10 below.
Figure 10. Network Management System using SNMPc
For information that is not supported by a standard SNMP MIB library, Advantech provides a private
MIB file that allow NMS software have the method of obtaining this information. To add a private MIB
into your NMS software, we need to compile the Advantech private MIB file into the library as the
example using SNMPc shown in figures 11 and 12 for private and public device information.
Figure 11. Add Private MIB into MIB library of NMS software
Technical Insights
Nov, 2014
Figure 12. Device information provided by Public MIB and Private MIB
As well as device monitoring, the ProView series of switches allow IT to control or perform certain
configuration through SNMP. The setting of the device location, device IP mode, device IP, device
netmask, default gateway and read/write community name can be configured directly through the NMS
software.
For the statistical port information, ProView switches are able to provide statistical information
including count on unicast, multicast and broadcast packet for each individual Ethernet port.
Table 13. ProView Switch port status and statistic using SNMPc
Technical Insights
Nov, 2014
ProView switches support SNMP traps which will automatically notify the SNMP server when there are
events such as port link-down/up, cold start and warm start occurs. This information allows IT engineers
to be notified of a network status change, not just on the ProView switch, but also on the devices
connected to it, imminently and act quickly. In figure 14 below, it shows the trap message example in
the SNMPc.
Figure 14. ProView Switch send out SNMP trap to server to notify the server the occurrence of events.
Technical Insights
Nov, 2014
For the complete SNMP function list, refer to table 3 below.
MIB File
Name
system:
sysDescr
sysObjectID
sysLocation
sysContact
SysName
interface:
ifNumber
ifTable
ifIndex
ifDescr
RFC1213
ifSpeed
ifOperStatus
ifInOctets
ifInUcastPkts
ifInNUcastPkts
ifInDiscards
ifInError
ifOutOctets
ifOutUcastPkts
ifOutNUcastPkts
ifOutDiscards
ifOutErrors
snmpMIB:
SNMPv2 snmpTraps
coldStart
warmStart
MIB File
Name
ifMIBObjects:
ifXTable
ifName
ifInMulticastPkts
ifInBroadcastPkts
ifOutMulticastPkts
ifOutBroadcastPkts
ifHCInOctets
ifHCInUcastPkts
ifMIB
ifHCInMulticastPkts
ifHCInBroadcastPkts
ifHCOutOctets
ifHCOutUcastPkts
ifHCOutMulticastPkts
ifHCOutBroadcastPkts
snmpTraps
LinkDown
LinkUp
system:
sysModelID
sysImageVersion
ipAddress:
ipMode
ipAddress
Advantech
netmask
ProView
defaultGW
MIB
etherAddress:
etherAddr
snmpConf:
snmpVersion
readCommunity
writeCommunity
trapServerIpaddr
Table 3. SNMP MIB table
Technical Insights
Nov, 2014
Port-Based QoS for deterministic data transmission
There are a maximum of two VIP ports with high transmission priority which can be used for
deterministic data transmission. The priority ratio between the VIP port and the normal port is 1.5 to 1.
For example, when there are two traffic flows on a ProView switch at the same time. When traffic flow 1
is transmitting data from VIP port 1 to port 5 and also traffic flow 2 is forwarding data from port 3 to
port 5, traffic flow 1 can have 50% more throughput than traffic flow 2. The port base QoS is useful to
ensure high priority on important data to be transmitted in a busy network.
Figure 8. Port Based QoS
Wide operating temperature range from -40 to 70°C
ProView series switches are designed to work in any harsh industrial environment. They are able to
function in wide operating temperatures ranging from -40 to 70°C. These wide operating temperature
unmanaged switches provide rock-solid, worry-free stability and industrial-grade performance.
Jumbo Frame up to maximum of 9,216 Bytes
All ProView series switch support jumbo frames up to 9,216 bytes. Jumbo frames can significantly
increase your network’s throughput while consuming fewer CPU cycles.
Technical Insights
Nov, 2014
Power saving with Energy Efficient Ethernet Standard, IEEE 802.3az
The ProView series switch fully meets the Energy-Efficient Ethernet (IEEE 802.3az) standard.
By supporting IEEE 802.3az standard, the Ethernet port on the ProView series can switch between
higher power state (data mode) /lower power state (LPI mode) in response to whether data is flowing
through them. This allows power saving up to 60% in average, ProView series switches saves you energy
costs and provide unquestionable industrial-grade performance and stability.
Figure 9. IEEE802.3az allow ProView switch to save power up to 60%.
Technical Insights
Nov, 2014
Loop Detection
All ProView switches come with built-in loop detection and LED indicator. This can help prevent careless
network deployment. During a complex network deployment, system installation staff may accidentally
connect the device with the wrong cable and cause a loop back on the network which can eventually
create a broadcast storm and in the worst case, melt the network.
Figure 10.Loop Detection LED for easy diagnostic.
On the ProView switch, in the case of a loop detection, the “Loop Detection” LED indicator on the device
switch will instantly light to notify the installer and remove the connection just installed.
Conclusion
With the communication capability using both Modbus/TCP and SNMP protocol, the ProView series of
switches are the very first networking switches in the world that provides management convergence
between industrial control and IT networking management. The ProView series of switches are
positioned in between unmanaged and managed switch to introduce a simple and cost effective
solution for increasingly complex industrial networking.
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