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ipRouteDialupIEC 870-5-101 router to connect RTUs and SCADA systems over dialup lines
ipRouteDialup Use Cases
Protocols
Features
Configuration
Diagnostics
Logging
Preconditions
Further information
Hardware
References
Our dial-up adapter ipRouteDialup is an IEC 60870-5-101 based router. ipRouteDialup
enables communication via a dial-up connection (PSTN) between a superordinate
control station and any device (slave) that does not have its own dial-up
functionality.
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ipRouteDialup supports Hayes compatible
analog modems, ISDN and GSM modems. Data transmission is based on the IEC 60870-5-101
protocol, either in balanced or unbalanced mode. The communication mode may be
chosen for each direction - uplink and downlink - separately.
As one serial interface is reserved for the uplink modem
connection, three interfaces are available for connecting substations. These can
be operated either in point-to-point or party-line communication (unbalanced).
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Protocols
ipRouteDialup supports nearly all the link layer functions defined by
the IEC 60870-5-101 protocol. The various protocols can be combined as
required.
| Uplink |
IEC101DialupSlave
IEC 870-5-101 dialup, slave |
For connecting control stations via a dial-up line. Both, balanced
and unbalanced communication are supported. |
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| Downlink |
IEC101Balanced
IEC 870-5-101 balanced, master |
For connecting substations via a conventional serial leased line
using balanced mode. |
IEC101UnbalMaster
IEC 870-5-101 unbalanced, slave |
For connecting substations via a conventional serial leased line
using unbalanced mode. The system supports simultaneous connections to
several substations. |
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Features
ipRouteDialup offers a full range of functions for communication control,
the most important ones are described below.
Connection setup and
teardown |
ipRouteDialup can be called by the control station any time. Once
the connection setup is successful, the buffered data is transmitted.
Connection setup can also be initiated by the substation, if the
following requirements are met:
- The dialup adapter has received an ASDU from the substation - for
instance a spontaneous indication - the type of which qualifies for
setting up a connection, as defined in the configuration. In
addition to the ASDU type, a cause of transmission may be
configured, which then initiates the dial-up.
- The telegram buffer (as configured in the size parameter) has been
filled to a specified limit.
- In predefined cyclic intervals (configurable).
A configurable character string can be sent to support identification
of the substation by the control station.
Connection takedown is initiated if either the maximum idle time
(i.e. no ASDUs are sent) or the maximum connection time is exceeded. If
the reason for connection setup persists after the disconnection,
ipRouteDialup automatically calls again after a configurable timeout. |
Intelligent data buffering
flow control
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While the uplink connection is down, all ASDUs received by the
substations are temporarily buffered. Buffer size is configurable. When
a configurable buffer limit is reached, ipRouteDialup sets up a
connection to the control station to dispatch the data. When the maximum
buffer limit is reached, data transmission is suspended (DFC bit) until
the buffer has been emptied to avoid buffer overflow.
Special measures are taken to prevent buffer overload by the inflow of
measured values. Measured values without a time stamp are entered in a
separate impulse buffer where each new value overwrites the older so that only the most recent value for each information object is
waiting for transmission. When a measured value with time stamp is
received, the relevant entry is deleted from the impulse buffer and the
new value is entered directly in the normal buffer. But, if configured,
a measured value can still trigger dial-up to the control station.
Accurate monitoring of the ASDUs ensures that a temporary connection breakoff or other communication interference does not result in
data loss. Unacknowledged ASDUs are repeated after the next connection
setup, even if they had been sent before. |
| Modems |
ipRouteDialup supports any Hayes compatible modems, analog, ISDN and
GSM modems. They can be configured freely via the web interface (for
details refer to configuration). ipRouteDialup features automatic modem
type detection, so that you may use different vendor modems without
having to reconfigure the system.
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| General poll |
As the master does not directly register a substation connection
failure, ipRouteDialup allows the automatic triggering of a general poll
to the substations after the next connection setup. |
| Clock sync |
ipRouteDialup features clock synchronization for substations. The
internal clock can be synchronized via NTP or IEC. Following its own synchronization,
any connected substations
are synchronized. |
Configuration
System configuration is completely executed in a web browser.
No other special configuration tools are required, a normal notebook with a
network interface card and web browser are all that is needed.
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The first page provides access to all relevant functions
of ipRouteDialup and shows the general system state at a glance. The following functions
are available:
- Backup and restore the complete configuration
- Software upgrade
- Edit configuration parameters
- Start up and stop the system
- Access diagnostic data (see also diagnostics)
- Access current log files (see also logging)
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| System configuration involves only a few parameters.
In addition to some general system parameters, such as ASDU address length and
information object address length, the link and transport modules need to be
configured for each transmission direction. As ipRouteDialup
simply passes through ASDUs, information objects need not be
configured directly. ASDU types that initiate dial-up to the control
station are configured in a list. |
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This is the configuration page for the IEC101DialupSlave
module which handles communication to the superordinate control station as
well as
modem control. Eligible modem types can be configured here. All modem
types shown in the dropdown list have been tested on the system. |
| Modem configuration page. Next to the modem detection
sequence, the user can enter several character strings that are sent to the modem
during initialization.
The character string for dial-up to the control station is
configured here, too. The dial number is taken from a separate list.
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Diagnostics
The diagnostic display offers a quick and detailed overview of
the communication state on all configured connections.
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The "Diagnostics" button on the first page
provides access to
diagnostic information. The most important information is displayed in plain
text format with the time in a clear and easy to read way. Colored highlights
indicate an ok / not ok status. The relevant information is shown for each
connection separately. In addition to information on the communication state of the
link and transport layers, statistical data is given. This includes the
number of ASDUs transmitted per minute on a specified connection. For uplink
connections, the buffer state is displayed to facilitate fast detection of
communication bottlenecks.
Connection setup with ipRouteDialup can be initiated from here, or if
a connection is up and running, connection takedown which significantly
facilitates the commissioning phase.
The current modem state is also displayed. |
Logging
With all communication applications, it is always essential
to know which data is transmitted via a protocol and how the data is
converted from one protocol to another. And it is even more important when
problems occur with transmission. ipRouteDialup features logging and archiving
functions for all data traffic.
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ipRouteDialup allows you to keep track of the system state and
information flow inside the converter by recording and archiving all
information passing through a module for a given time period. The following data
can be recorded:
- All data to/from ipRoute sent and received via the relevant
communication module
- System messages, i.e. connection break-off,
communication error messages etc.
- Configuration and software error messages
The range of data recorded is defined by the logging level. This can be
changed dynamically (at runtime) or statically (in the configuration) for
each module. |
| The logging level defines the
representation format for the sent or received information. Data can be
represented either in hexadecimal code or in decoded, symbolic form or both.
This example shows the content of a logfile generated from the
IEC104 server module. Data is stored directly in the easy to read ASCII
format. Logfiles can be
downloaded via a web interface for offline diagnosis. Or you can keep
track of the communication online via the TCP/IP "telnet" service.
All recorded data is archived cyclically, enabling you to keep track of
communication over a period of days or even weeks (depending on the data
volume). |
(2): << [1/1] I-FRAME NS=8377 NR=4 DATA=<01 02 03 00 01 00 0
(2): << [1/1] I-FRAME NS=8378 NR=4 DATA=<01 02 03 00 01 00 0
08.03.05 14:55:11 up1 [1/1] path disconnected !
08.03.05 14:55:11 up1 [1] connection aborted !
08.03.05 14:57:39 up1 [1/1] path connected !
08.03.05 14:57:39 up1 [1/1] connection established with 192.
(2): >> [1/1] LEN=4 STARTDT ACT
(2): >> [1/1] LEN=20 I-FRAME NS=0 NR=0 DATA=<67 01 06 00 FF
(2): >> [1/1] LEN=14 I-FRAME NS=1 NR=0 DATA=<64 01 06 00 FF
(2): << [1/1] STARTDT CON
(2): << [1/1] I-FRAME NS=0 NR=2 DATA=<67 01 07 00 FF FF 00 0
(2): << [1/1] I-FRAME NS=1 NR=2 DATA=<01 02 03 00 01 00 02 0
(2): << [1/1] I-FRAME NS=2 NR=2 DATA=<64 01 07 00 01 00 00 0
(2): << [1/1] I-FRAME NS=3 NR=2 DATA=<01 3B 03 00 01 00 02 0
(2): << [1/1] I-FRAME NS=4 NR=2 DATA=<01 3B 03 00 01 00 01 0
(2): << [1/1] I-FRAME NS=5 NR=2 DATA=<01 3B 03 00 01 00 02 0
(2): << [1/1] I-FRAME NS=6 NR=2 DATA=<01 3B 03 00 01 00 02 0
(2): << [1/1] I-FRAME NS=7 NR=2 DATA=<01 3B 03 00 01 00 01 0
(2): >> [1/1] LEN=4 S-FRAME NR=8
(2): << [1/1] I-FRAME NS=8 NR=2 DATA=<01 01 03 00 01 00 02 0
(2): << [1/1] I-FRAME NS=9 NR=2 DATA=<01 02 03 00 01 00 01 0
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Preconditions
These requirements ensure successful integration of IEC 870-5-101
systems:
- Common ASDU (CA = Common Address of ASDU) and the information object
address (IOA) must be of the same length
- ASDU types used for the control station or substations must be compatible.
This can be ensured by matching interoperability lists.
- ASDU addresses must be unambiguous and unique for all connections,
multiple assignations are not allowed .
If these requirements cannot be met, ipConvLite or ipConv are
alternative options.
We would be more than pleased to offer our support to assist you in checking these requirements.
Further information
| Booklet |
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Hardware
 | HEC | Compact controller mountable on a DIN-rail specially suited for decentral applications Details...
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References
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