Chapter 8. Industry Sectors

Table of Contents
Electric Utilities
Gas Industry
Water Industry

Electric Utilities

ELCOM-90 : rules for result code 128..254

Thu, 16 Jan 97 16:39:00 GMT

Hello, My project group is developing several communication links between SCADA and EMS systems of electricity utilities using the ELCOM-90 protocol. We are faced with the following problem : According to ELCOM-90 each API call can return a result code form 0..254. Values from 0..127 are reserved but values from 128..254 are system implementation dependent reason. Do you known if some rules are defined (by the ELCOM-90 community ?) for the numbering of these values (128..254) ? Thank you,

Patrick Jacobs                               
Ph   ++32 2 773 88 78 TRASYS                   
Fax ++32 2 773 79 30 
Energy Product Line

ref: c:/emacs/industrysectors/msg00006.sgml

DMS-Safety Switching Schedule

Tue, 1 Apr 1997 15:09:20 -0500 (EST)

Hello, I am working on a Distribution SCADA Project for a customer in England. One of the requirements for the customer is a "Safety and Switching Schedule" function. It's basically an off-line Maintenance management system, wherein the operator is instructed to follow a pre-defined switching sequence/ schedule inorder to carry out any operation on a Breaker, Isolator, Power Transformer etc. If anyone has worked on such a system or developed one, I would really appreciate the gesture of throwing more light on this topic. Warm Regards,

 Melbourne, FL 32934
 Phone : 407-752 8917
 E-mail :

RE: DMS-Safety Switching Schedule

Wed, 02 Apr 97 11:49:00 GMT

We delivered several SCADA systems to Electrabel, the Belgian Utility. Our customer, Electrabel, developed a software package called LIMA for "LIste de MAnoeuvres" that covers the requirements you described. They intend to couple this off-line package with their SCADA systems in order to get an on-line supervision of the switching sequence. You could try to contact Herwig Vandenbosch from Electrabel ( for further information. He suggested also you could have a look to the report of the CIGRE september 92) : 38-106 Génération automatique et interactive de listes de manoeuvres pour un réseau complexe THT-HT. Regards,

 Patrick Jacobs                E-mail :
 Trasys S.A.                    tel.        : +32 2 773 88 78
 Energy Product Line fax.       : +32 2 773 79 30
 Avenue Ariane, 7
 1200 Brussels

Re: DMS-Safety Switching Schedule

Wed, 2 Apr 1997 7:57:41 -0600

Interesting concept - the maintenance switching. I would say that we did something very similar at PSEG when I was there - its called SUFW (set up for work) - the command basically turned on instantaneous and turned off reclosing on a breaker or recloser to make the unit ready for downstream line work. There is no reason this could not be extended to actual switching operations - think of it as a spreadsheet macro - you push one button to execute several predetermined commands. Regards,

 Doug Staszesky                       Email: DSTASZESKY@SANDC.COM 
 Manager - Product Marketing          Phone: (773) 338-1000 X2560 
 SC Electric Company                 Fax:   (773) 338-4814
 6601 North Ridge Blvd.
 Chicago, IL 60626

Re: DMS-Safety Switching Schedule

Wed, 2 Apr 1997 13:12:49 -0300

Rajsekar We sold several SCADA systems to electric substation monitoring and control. Some of our customer ask us to implement a pre-defined switching sequence like:

- isolate a breaker;

- transfer a breaker to a specific bay for maintenance aspects;

- etc. To solve this customer needs we defined some elements in our SCADA software. I will present you this elements in a resumed way, maybe it can help you. The elements involved in our implementation are:

a)- Time schedule It's a programmable time schedule matrix that can be associated to any process variable (DI,DO,AI,AO or calculated) or a recipe. It will cause a significant event. To each variable you can have more then one matrix (normal, weekend, special and eventual)

b)- Significant Event and Event Process A significant event is:

- occurrence of a time schedule;

- one variable (input, output, calculated) assume a defined range value

- Change the status of a variable;

- Variable return to a specified status;

- Receive a message;

- Occurrence of an alarm/event;

The SCADA has a real time event process that activate the element associated to the event:

- activate a standard method (see d);

- Activate as user method (see d)

- Recalculate a formula using updated values;

- Activate an recipe

- send a message to an external process;

c)- Recipes (Automatic switching) Can be activated by:

- Operator command;

- Event Process;

The recipes are a kind of simple scripts where you have implemented:

- sequence of methods;

- expressions using data base tags of variables;

- If then else

- Do until

- Call another recipe;

- time delay

d)- Methods There are two kind of the methods:

d1)- Standard: like digital output, analog output, etc. that are available in the SCADA software as OLE-DLL functions;

d2)- The user defined methods: are programs or OLE-DLL developed by the users according their needs or the peculiarities of their process. This functions access the real time data base using API calls to a SCADA DLL.

Concluding, you can implement a pre-defined switching sequence as result of the execution either a recipe or an user method. Once these sequences are common to several users, they can develop general methods useful to different users applications an make it available in a library. Regards,

 Clovis Simões
 Spin Engenharia de Automação ltda

Ref: c:\scada\041997\msg00007.xml