Change Management of SASensor
A particular concern has always been the manageability of substation automation systems during there lifecycle. Concerns in terms of changes made to the system, testing of changes, retention of the detailed technical knowledge of a particular system. The lack of awareness of the necessity of version control of the applied components and software modules within the utility have led to many fierce discussions regarding the change management of substation automation systems.
Digital secondary systems are composed of hardware and software. System parameters, process parameters and functional parameters needs to be managed. Identification of individual recognisable items is in most cases done by version numbers.
To manage specific configuration parameters and operating parameters a different approach is chosen within SASensor. Although the file storage might give a date/version indication the user is more interested in the difference of the content between two versions, than the fact that the files are just different.
Integrated difference analysis tools give the engineers full control of what they are doing and the capability to see differences, accepting/rejecting them and ultimately using a roll back facility when they lost track completely. Change management tools are of utmost importance to stay in control of what is going on.
Automated Backup
An important function of the system is the backup facility. With a central server in the office or remote control centre it is possible to obtain fully automated system management. “The power of simplicity” reaches up to here as well.
Intranet / WAN communication
VPNs (Virtual Private Networks) are used to provide cost-effective mechanisms for private IP services over a public infrastructure. VPN methods used are e.g. filtering, tunnelling and cryptography. The security aspects of the system are implemented in the Connection Manager.
Essential for security is authentication. Only when both computers agree that they can trust the other, a virtual tunnel is created. A personalised digital signature on a USB-stick for each individual employee supplies the system with the required authorisation and identification data.
A tunnel is just a special type of connection across a network. It is done in a way to make the tunnel resemble a direct wire connecting between two computers.
Tunnelling enables remote users and distributed private networks to communicate with a relatively high degree of security over public networks. Simply, tunnelling is the ability to create circuit-like connections across a packet-oriented WAN (Wide Area Network). In a communication tunnel, a private point-to-point connection is established between endpoints in an IP network. Tunnels work in a similar fashion to virtual circuits. End-users can put any type of traffic, even non-IP traffic, into the tunnel.
Additional security measure such as cryptography is used in conjunction with tunnelling to further bolster VPN security.
The Connection Manager enables accessibility for all authorized employees from any arbitrary location. Reading the on-line and stored data, and even upgrading of operating, system and application software can be done remotely in a secure manner of course depending on the authority and rights of the employees.