Network configurations and operating modes

The telecontrol components support the set-up of complete hierarchical communication networks comprising terminals, node stations and control center.

For the exchange of information between the individual devices, conventional WANs can be used, such as dedicated-line, wireless and dialup networks as well as IP-based WANs such as DSL, GPRS, UMTS, Internet, etc.

There are no restrictions on the combination of WAN types in a project. Point-to-point, line and node network topologies can be set up. Hybrid configurations of these basic structures are also possible.

A station can be linked using two transmission paths to permit redundant data transmission. The two paths can be of the same type or different, e.g. dedicated line plus GPRS, or ISDN plus wireless.

The following network topologies are possible in the WAN:

• "Point-to-point"
• "Line"
• "Star"
• "Tree"
• "Ring"

The graphics below show examples of different network topologies that can be implemented with the components listed above.

SINAUT ST7cc/sc control station with redundant WAN connection

Different communication media in a SINAUT ST7 system

The control center

A number of different variants can be selected as components of the central control center:

SINAUT ST7cc;
PC control center based on WinCC;
this is the ideal control center system for both SINAUT ST7 and SINAUT ST1. It has been designed specifically for event-driven and time-stamped data transmission on the SINAUT system and can be set up as a non-redundant or redundant system (to supplement the WinCC/PCS 7 redundancy package).

PCS 7 with PCS 7 TeleControl;
this is the ideal control center system for plants in which larger local automation tasks have to be combined with telecontrol connections. In addition to SINAUT ST7, remote stations with other communication protocols can be connected, e.g. over DNP3 or IEC -60870-5-101/-104. ¹⁾

WinCC TeleControl;
control center system for plants with the WinCC HMI software, expanded with telecontrol connections. WinCC TeleControl offers connection of SIMATIC substations with TIM 3V-IE DNP3, TIM 4R-IE DNP3 or non-Siemens stations with DNP3 protocol, as well as telecontrol stations with IEC-60870-5-101/-104.

SINAUT ST7sc;
OPC server for interfacing control centers from other vendors via the OPC Client function;
the SINAUT telecontrol technology can also be connected to control center systems from other vendors via the "Data Access Interface". ST7sc features extensive buffer mechanisms which prevent data from being lost even if the OPC client fails. It can be connected to non-redundant or redundant clients.

Like the substations, the control center comprises a SIMATIC S7-300 or S7-400 PLC.
This solution is suitable for simpler control centers in which only an up-to-date process image of the process data available in the stations is required. The station process control can be influenced by entering commands, setpoints or parameters. This S7-300 or S7-400 control center can also be used to extend a PC control center (SINAUT ST7cc or ST7sc), e.g. for data output on a panel and/or as an emergency operating system.

SINAUT ST7cc control center system with connected substations (RTU)

Classic WANs

The following conventional WANs can be used for data transmission:

• Copper dedicated lines, private or leased
• Private wireless networks (optionally with time slot procedure)/TETRA
• Dial-up networks (analog/ISDN/GSM)

IP-based WANs

SINAUT communication, however, is also possible via IP-based networks:

• Wirelessly, by using special wireless systems optimized for Ethernet, e.g. the components of the SCALANCE W IWLAN system
• Via fiber-optic conductors, e.g. through use of SCALANCE X switches with optical ports; distances of up to 120 km can then be covered
• Via public networks and the Internet using DSL or GPRS/UMTS
• Copper dedicated lines, private or leased

Change-driven data transmission

In the stations, the SINAUT software ensures that process data is transmitted between CPU and control center, e.g. ST7cc, and from CPU to CPU in the event of changes. Connection, CPU or control center failures are displayed. A data update for all participating communication partners is performed automatically following debugging or startup of a CPU or of the control center.

Permanently correct time

To enable subsequent and correct archiving of process data in the control system, all data frames are already assigned a time tag at their place of origin. The entire network is synchronized automatically – including daylight saving time changeover.

Local data storage

A special property of the TIM communications module used in the SINAUT ST7 system is the capability for saving data which must not be lost in the event of a connection fault or if the partner fails. A memory capacity is provided for up to 56,000 message frames.

The memory capacity helps to save money on dial-up networks. Various priorities can be assigned to the data to be transmitted. At high priority, a dial-up connection is established immediately. At low priority, data is initially saved in the TIM. This data is transmitted on the next connection that is made with the partner for any reason, for example if an item of information with a high priority is to be transmitted, or if the partner sets up a connection in order to exchange data.

It is precisely because the TIM module can save data and transmit it at a later point in time with a time stamp that the use of a suitable control center system must be ensured. It must also be possible to continue to process this data, specifically as regards subsequent archiving, if the data is received in the control center delayed by a number of hours or even days. Also archive compressions such as the creation of mean, hourly and daily values cannot be performed until all data for the relevant period has been received. The standard SINAUT control center on the basis of WinCC, when supplemented with the SINAUT software ST7cc, is ideal for this task.

SINAUT remote programming and remote diagnostics

In industries in which SINAUT is used, the terminals are distributed across wide areas and are often situated in locations that are difficult to access. Faults which require a visit to be made to a terminal of this type are associated with long journeys. SINAUT ST7 can provide the ideal solution for such circumstances: Remote programming and diagnostics via the telecontrol network. All diagnostics and programming functions provided by SIMATIC and SINAUT for station automation and WAN communication can be used via the telecontrol path - without interrupting process data transmission.

Alarm messaging via text message

In order to alert standby service personnel, event-driven text messages can be sent to mobile phones from the CPUs. An acknowledgment that a message of this type has been received can be sent back to the sender CPU from the mobile phone. A text message can also be output as e-mail, fax or voice mail if the mobile service provider offers these options.

¹⁾ For further information, see Catalog ST PCS 7.1