the scada connection - moving beyond auto dialers
DESCRIPTION
SCADATRANSCRIPT
Auto dialers have a long history of providing notifications in remote SCADA
(Supervisory Control and Data Acquisition) installations. Most auto dialers detect
possible alarm conditions by using discrete digital and analog ports connected to
sensors. Once a problem is detected, appropriate users are notified when the
device calls one or more pre-defined phone numbers to report the alarm
conditions.
While auto dialers are in some cases an effective way to remotely monitor pumps,
valves, motors and switches, the evolution of SCADA installations have resulted in
more complex equipment on site that needs to be monitored and controlled. There
is also a greater demand by SCADA users to optimize operations by automating
functions that can be done remotely in order to eliminate the costs and time
required to send a technician on site to verify the existence of a problem, diagnose
the root cause and plan for remediation.
In this white paper, we will explore how SCADA installations can evolve from the
use of auto dialers to a more comprehensive way of managing remote sites that
increases visibility while reducing the costs.
SCADA technology is used in a number of industries including the oil and gas,
electricity, and water and waste water industries. It is used to monitor and control
equipment of all sizes and complexities. SCADA systems gather information such as
pump on/off events, liquid flow, water levels, pressure values, and temperature
readings and send them to a central management system.
Traditionally, SCADA system operators were looking for confirmation of basic
functionality and to be notified when abnormal events occurred. Examples of
events include:
- Levels above/below predetermined thresholds
- Pump/generator on/off events or excessive starts
- Intrusion detection
- Power loss
- Temperature readings or pressure values above/below thresholds
These types of events are easily reported by simple auto dialers using conventional
phone lines to report when values have crossed high or low set points.
However as SCADA systems have evolved and operators increase their demand for
information; some data cannot be easily communicated using auto dialers over
analog phone land lines.
Wireless communication has enhanced the possibilities when it comes to SCADA
monitoring. Operations managers are no longer restricted to relying on auto dialers
connected to phone lines for communicating SCADA events.
Operations managers can now have more physical reach by being able to monitor,
control and automate equipment located at remote sites spread over large
geographical areas. It has also been part of the evolution that allowed customers to
move away from closed, analog connections to digital and IP (Internet Protocol)
based systems.
As technology has evolved, SCADA remote monitoring and control equipment like
PLCs (Programmable Logic Controllers) and RTUs (Remote Terminal Units) have also
become more feature-rich (and complex). The increase in proliferation and
functions in PLCs and RTUs means there is a greater richness in information
available locally to operations managers. However, the challenge is to exchange
information with the equipment in a timely manner and make it available to the
SCADA master station and HMI (Human Machine Interface) for viewing,
interpretation and driving business KPIs (Key Performance Indicators).
Whether you are building a new remote SCADA site or retrofitting an existing site,
there are many points to consider so that you are able to extract richer
information. Building (or upgrading) a successful SCADA network depends not only
on understanding today’s remote monitoring and control requirements but
implementing a system that can scale to tomorrow’s needs.
Beyond the master station, there are three main components of the SCADA
network that need to be selected when looking at the architecture of the SCADA
network. These are:
1. Controllers or Data Terminal Equipment (DTE) at the remote sites
2. Data Communication Equipment (DCE)
3. Communication (telemetry) network
Today’s controllers, whether they are PLCs, RTUs or intelligent communication
terminals, come in various sizes and capabilities to meet master station and remote
station control needs. Here are 10 things to consider when selecting this type of
equipment:
1. Local Intelligence and Processing: Is the unit programmable? What is the
processing throughput? What is the data logging capacity of the unit?
Cellular
network
Head Office/
SCADA HMI
SCADAconnect
Enterprise
gateway
Satellite
network
Telemetry data IsatData Pro
network
SkyWave
communication
device
SkyWave
communication
device
SCADAconnect
Asset gateway
SCADAconnect
Asset gateway Telemetry data
2. Input/Output (I/O) ports: What is the number of I/O ports and what is
their accuracy? Do they meet the needs of the application?
3. Communications: What telemetry communication services are supported?
Are there provisions for redundant communications for critical
applications? Can data be sent and received at a frequency required by the
application and the operation manager?
4. Protocols: Does the unit support open standard industry protocols like
Modbus and DNP3 on serial and TCP/IP ports?
5. Interfaces: What interfaces are required to connect to DCEs?
6. Power: What are the power requirements of the units? Can the unit be
operated on battery alone? What are the options for backup power?
7. Enhanced Security: Does the equipment support password-protected
programming, authentication and IP firewall capabilities?
8. Durability and Ruggedness: Is the unit rated to handle the temperature,
humidity, vibration and electrical conditions found at the remote sites?
9. Modularity: Is the unit expandable as demand and needs change?
10. Space and Installation: How much space is required by the controller and
how will it be installed at the remote site?
SkyWave Products as Data Equipment Terminals for unmonitored SCADA sites
In some applications, SkyWave satellite devices are a very cost-effective way to add
a controller with communication capability to a remote SCADA site. The IDP 600
series terminals feature four (4) general input/output ports for connecting analog
and digital sensors. The terminals also have RS-232 and RS-485 ports for connecting
devices that communicate via serial protocols like Modbus.
The onboard processor on the devices allows customers to program logic into the
device to react events like “Send a notification when the water level is above the
analog high threshold” or “close the valve when pressure reading is below low
threshold”. This “edge analytics” capability reduces the amount of data that is sent
wirelessly, thereby decreasing the time to react to events as well as monthly
airtime costs.
Learn more about IDP 600 series terminals at www.skywave.com.
SkyWave Solutions for SCADA sites with PLCs and RTUs
For SCADA sites with PLCs and RTUs, SkyWave offers SCADAconnect - a three-part
application that includes an asset gateway that quickly and easily connects to
remote PLCs and RTUs to extract data; a communication modem for relaying data
from remote sites to enterprise applications; and an enterprise gateway to
interpret the data from remote sites and insert them into the SCADA HMI (Human
Machine Interface) system.
The asset gateway allows customers to not only extract data from the PLC but also
to provide the edge analytics portion where only relevant information is sent to the
SCADA HMI system. For example, an operations manager can be notified only when
the fan speed changes by 5%. Anything below that would not be reported, thereby
reducing communication costs and “data overload’ syndrome.
Learn more about SCADAconnect at www.skywave.com.
DCEs are responsible for the exchange of appropriate data between
controllers/DTEs and the master station using the communication network. DCEs
include auto dialers, as well as radio, cellular and satellite modems and terminals.
Here are 10 things to consider when considering DCEs for SCADA sites:
1. Availability: Which communication networks are available at the remote
sites will drive the selection of the DCE. Options include radio, private
leased lines, cellular and satellite.
2. Redundancy: Does the DCE have redundant communication options?
3. Data Requirements – Does the unit support the transmission of analog,
digital and/or serial data?
4. Data Communication Rate: How much data needs to be sent to and from
the remote site? Will the data demand change as the site grows or evolves?
Can data be sent and received as frequently as required and desired?
5. Transmission Modes: Does the site need half-duplex or full-duplex
capability?
6. Response time and Latency: How much time does it take to relay
information between the controllers and the master station? Does it meet
the needs of the application?
7. Interfaces: What interfaces are required to connect to the controllers?
8. Standards and Certification: What communication standards need to be
complied to operate in that region?
9. Power: How much power is required to operate the DCE? Can the unit
revert to backup power in the advent of a failure on the main power line?
10. Durability and Ruggedness: Like the controllers, is the unit rated to handle
the temperature, humidity, vibration and electrical conditions found at the
remote sites?
SkyWave Products as DCEs
An integral part of SkyWave technology is the ability to provide cost effective
satellite communications for remote sites requiring the ability to send notification
of events and alarms as well as regular telemetry data. Since the system uses the
Inmarsat satellite constellation, customers who opt for this solution have the ability
to send and receive as much data as they want without being constrained to using
time slots at specific times of the day. They also receive the information in seconds,
rather than minutes or hours.
The IDP 600 series satellite-only devices are
rugged and compact. They are designed to
be installed outside and are also available
with C1D2 (Class 1, Division 2) certification
for use in hazardous locations.
The IDP 700 series satellite-cellular devices
are equipped with more than 17 I/O ports and can send information via satellite,
cellular or both, depending on need.
See satellite and satellite/cellular devices in action at www.skywave.com.
IDP-680 C1D2 Terminal
IDP-690 C1D2 Terminal
The communication network is the essential component for connecting remote
sites to master stations. When selecting the primary and secondary communication
systems, consider the following 10 things:
1. Coverage: Is the network available at the remote sites?
2. Uniformity: Looking at the entire SCADA system, is it important to use the
same communication networks across all the sites? Choosing different
networks depending on local availability will increase the number of DCEs
that need to be selected.
3. Infrastructure: Is there a need to install infrastructure like towers and
repeaters to support the communication network? What is the required
investment for infrastructure? Can infrastructure installation and
maintenance costs be outsourced to a provider like a cellular or satellite
communication provider?
4. Monthly Costs: What are the monthly usage costs?
5. Total Cost of Ownership: How does initial infrastructure and monthly costs
fit into company’s financial policies?
6. Reliability: What is the reliability of the communication network at each
remote site? Does it meet the mandated or desired service level
agreement?
7. Data Communication Requirements: How much data needs to be sent to
and from the remote site? Will the data demand change as the site grows
or evolves?
8. Transmission Modes: Does the site need half-duplex or full-duplex
capability?
9. Responsiveness and Latency: How much time does it take to connect to
the network and relay information between the controllers and the master
station? Does it meet the needs of the application? How frequently can you
poll or access data from remote sites?
10. Emergency Management: Does the communication network stand up to
extreme weather like hurricanes, tornadoes and tsunamis?
SkyWave Products and Communication Telemetry Networks
Think satellite is expensive? Think again. SkyWave devices are ideal for applications
that require cost-effective connectivity in remote areas where other
communication services are unavailable or cost-prohibitive to implement. In some
cases, customers who have chosen SkyWave solutions pay less than cellular
solutions.
In addition to costs savings, since SkyWave uses the Inmarsat satellite constellation,
data from SCADA sites are received within seconds, allowing operation managers to
react immediately to events. The system is also resilient to local weather events
like tornadoes and hurricanes since it does not rely on terrestrial towers.
Learn more about satellite solutions for your SCADA applications at
www.skywave.com.
The move towards increased visibility of at the status of remote SCADA sites and
collecting more data than provided by alarms (as offered by auto dialers) has
translated into significant cost and operational savings for managers. Benefits
include:
- Reduced field visits thereby decreasing labor and fuel costs
- Ability to schedule maintenance on equipment based on need, rather
than time passed
- Decreased MTTR (Mean Time to Repair) by receiving real-time alerts of
issues. Plus, being able to poll more data from the sites means being able
to diagnose the problem before dispatching a technician.
- Minimized downtime by being alerted of degradation in performance of
equipment
To achieve these results it is important to spend time considering the architecture
of your SCADA site including the Controllers or Data Terminal Equipment (DTE), the
Data Communication Equipment (DCE) and the Communication (telemetry)
network and how the solution can meet today’s remote monitoring and control
requirements but scale to tomorrow’s needs.
For more information about how SkyWave products can address your DTE, DCE and
communication telemetry network, visit us at www.skywave.com.
SkyWave Mobile Communications is a global provider of wireless data
communications for the Machine- to- Machine (M2M) market. SkyWave’s products
provide dependable communication, tracking, monitoring and remote
management of fixed and mobile assets. Over the past 16 years, SkyWave has
designed, manufactured and shipped more than 700,000 Inmarsat-based satellite
terminals to customers globally in the transportation, maritime, oil and gas, utilities
and government sectors. For more information, please visit www.skywave.com.
Inmarsat plc is the leading provider of global mobile satellite communications
services. Since 1979, Inmarsat has been providing reliable voice and high-speed
data communications to governments, enterprises and other organizations, with a
range of services that can be used on land, at sea or in the air. Inmarsat employs
around 1,500 staff in more than 40 locations around the world, with a presence in
the major ports and centres of commerce on every continent. For the year ended
31st December 2012, Inmarsat had total revenue of US$1,278 million and an
EBITDA of US$643 million. Inmarsat is listed on the London Stock Exchange
(LSE:ISAT.L). For more information, please visit www.inmarsat.com.