Cadec simulator

Cadec was a telecontrol system built by the Westinghouse Brake and Signal company in the late 70's for the South Eastern Electricity Board and installed and commissioned in the early 80's.

The control system was initially based on DEC PDP-11/34 minicomputers with DEC colour display controllers driving large colour monitors with bespoke keyboards. It was later upgraded to PDP-11/44 minicomputers using AYDIN display controllers again driving large colour monitors.

This system existed in use, upgraded to MicroPDP-11/93 microcomputers, until past the millenium and had to be Y2K upgraded by the development team.

This simulation is of the display for one control desk for the upgraded system. It was originally written in Borland Turbo C for a DOS PC using their conio library. I have added source files to convert this where possible to run on Windows using the Console API. As the original code used BIOS and DOS calls to control external devices such as a ding dong and to determine the presence of a dot matrix printer for printing logs, this functionality won't work and is not used.

The system is built using MSYS2 using the Makefile provided.

This repository does not contain the original database as this was an accurate copy of part of the network as it existed.

To prevent console escape sequences being generated by console input, select Use legacy console in the Cadec window properties dialog. Also select Lucida console 14 point font to get the best approximation of the Cadec display.

The database is a text file which can be edited with any text editor. Lines beginning with a ‘#’ are ignored by the system. The format is:

System values: trip probability, successful reclose probability, purple cursor probability and analogue jitter factor

VAL	5	75	2	5

Substation: spens number and name.

SUB	8305	ANGMERING 11

Switchgear: make and type.

SWG	REY LM23T

Tap changer: type.

TAP	SINGLE AVE 1

Equipment: SPENS, status, analogue 1, analogue 2, name.

EQU	00	0000	17	140	ANGMERING

The status value is in hexadecimal (base 16) and is made up of 16 bits. These are defined as follows:

8  4  2  1 |8  4  2  1 |8  4  2  1 |8  4  2  1  (Hex values)
15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  Open
|  |  |  |  |  |  |  |  |  |  |  |  |  |  Closed
|  |  |  |  |  |  |  |  |  |  |  |  |  Protection Off
|  |  |  |  |  |  |  |  |  |  |  |  Protection On
|  |  |  |  |  |  |  |  |  |  |  Auto Off
|  |  |  |  |  |  |  |  |  |  Auto On
|  |  |  |  |  |  |  |  |  Tripped
|  |  |  |  |  |  |  |  EFI Indication
|  |  |  |  |  |  |  Protection Operated
|  |  |  |  |  |  Auto Reclose Lockout
|  |  |  |  |  External Indications
|  |  |  |  External Output
|  |  |  Equipment is Trippable
|  |  Equipment has Protection
|  Equipment has Automation
Not Used

There are two copies of the database. CADEC.DAT is the backup, and is read if the work file CADEC.SAV is not found. The database is automatically saved to CADEC.SAV at 30 second intervals.

The alarm list is stored in a file called ALARMS.LOG. The format is:

875314032	8547	07	A C.B. TRIPPED

The fields are: date and time as an integer, substation, equipment and alarm text.

The event log is stored in a file called EVENTS.LOG. The format is:

26/09/97 18:47:12    8547 SOUTH WORTHING 00    SOUTH WORTHING   F PROTECTION OPERATED

The fields are: date, time, substation, substation name, equipment, equipment name and event text. The format of the event text varies wi th the type of event.

Every second the system checks to see if anything needs tripping. This is determined by the probability of trip value. If it does the equipment gets tripped, alarms and events are generated, and if auto reclose is available and on an auto reclose operation is started. If sensitive earth fault protection is available and on an EFI alarm will be generated.

Every second the system checks to see if any auto reclose operations are pending. If so, it decrements the timer, and performs a trial reclose when the timer matures. The success of the reclose is determined by the probability of successful reclose value. Alarms and events are generated according to the success or failure of the reclose.

Every second the system increments the keyboard timer and checks to see if it has run out. If so, the display is changed to the CADEC logo.

Every 15 seconds the voltage and current analogue values in the database are jittered. The system keeps a backup copy of the original value to ensure that analogues do not drift too far. The current display is refreshed if it is dynamic.

Every 30 seconds the system saves the database to CADEC.SAV.

Every time a command is entered the probability of a purple cursor is checked and if so, the cursor is turned purple and the system will not respond to the keyboard until a random timer has timed out.

Whenever an alarm is generated the system dingdong will initiate. It will continue to operate at 30 second intervals until a key is pressed.