3. Configuration
3.7. Configuring time handling
In general, the time synchronization of the SYS 600 system and connected IEDs is necessary in order to interpret correctly any time-stamped information provided by the system. The time-stamped information can be, for example, the event
information from the IEDs.
The SYS 600 system uses the internal clock of the computer as the source of time.
Depending on the configuration and the system structure, this clock may be synchronized from an external source such as GPS, radio clock or another SYS 600 system. The GPS clock reference device is connected through a SLCM card via a
LON line or using an external application. When the SYS 600 system is operating as a communication gateway, the synchronization is often received from the network control center through the used communication line. If IEC 61850 communication server is used in MicroSCADA PC, SNTP time synchronization can be used.
The same internal clock is used, when the real IEDs connected to the SYS 600 system are synchronized through the communication lines in process
communication units. In most of the communication protocols there is a predefined method to synchronize the IED. For more information about the synchronizing methods, refer to the protocol specific manuals. When SYS 600 is used to synchronize the IED, the synchronization command is usually initiated cyclically from the application running in the base system. The related station object attribute is SY for many protocols. In some protocols, there is a possibility for the IED to request a time synchronization from the master.
The process communication units running in the same computer use the same system clock, which means, there is no need to make separate synchronization for the unit. This is different from the DCP-NET units used with the older SYS base system versions, where the units had a separate clock in the used hardware.
When operating as a communication gateway, the network control center may operate in a different time zone. The corresponding compensation attribute is TZ which exists both in SYS:B object and NET:S object (only for process
communication unit PC-NET).
3.7.1. Configuring time synchronization
The time synchronization characteristics usually vary from one system to another and are strongly dependent on customer and/or IED requirements. The
communication protocol used, also has an effect. For example, with SPA-protocol the time synchronization command is sent every second. With some other protocol, the interval of the time synchronization may be hours.
The following steps should be considered when the time synchronization concept for a SYS 600 system is planned:
1. Find out the system requirements.
2. Resolve the clock reference for the planned system.
3. Resolve IED requirements with the used communication protocol.
4. Define the synchronization intervals for IEDs or IED groups.
5. Define the time synchronization details of the used protocol.
In step 2, it is defined if the clock of the SYS 600 computer is synchronized from an external source. This source could be a network control center or a radio clock device connected to a communication line in PC-NET, an external application using SNTP server and/or GPS device, a SLCM-card connected to LON star coupler and so on.
If the source of the time is connected to communication line of the PC-NET, some configurations tasks may be required. For IEC60870-5-101/104 and DNP3.0 protocols, refer to corresponding slave protocol manuals, station attribute TC. For LON protocol, refer to System Objects manual. The time zone compensation is done with attribute SYS:BTZ.
If the source of the time is an external application or a special device, refer to the corresponding manuals for more information.
In step 3, the requirements of the used IEDs are defined. These requirements may define the minimum frequency of the incoming time synchronization or it may require that the synchronization should be preceeded by a delay measurement. The IED may also define if it accepts the time only with or without date or only as a broadcast message. It is also possible to synchronize the device from an external time source and it need not be done from SYS 600 at all.
Steps 4 and 5 require SYS 600 application programming. With protocols implemented to process communication unit PC-NET, a common practice is to define a time channel or a set of time channels which are executed with a defined interval. A command procedure which actually initiates the synchronization is then connected to the time channel.
Example for DNP3.0 master protocol:
#LOOP_WITH I=20..25
#IF STA’I’:SIU==1 AND STA’I’:SOS==0 #THEN #BLOCK
#SET STA’I’:SSY=(1,0) ; direct, no time delay measurement
#PAUSE 10
#BLOCK_END
#LOOP_END
If this procedure is attached to a time channel, which is executed with 1 hour interval, the IEDs related to STA20..STA25 are synchronized once every hour. The same station object attribute SY is used for time synchronization in most protocols implemented to PC-NET. For more details, refer to the protocol specific manuals and System Objects manual.
3.7.1.1. Configuring external clocks
DCF77 radio clock from Meinberg
The board PCI511 has been designed for the reception of the DCF77 signal, the transfer of the time information to a computer with PCI (PCI-X) bus interface.
Install the card to a free PCI bus card place. After switching on, it will ask to locate the place of the driver software.
The drivers package contains a monitor program (for more information, see Fig. 3.7.1.1.-1), which allows the user to check the status of the device. It is also useful to modify parameter configuration.
A070709
Fig. 3.7.1.1.-1 Configuring Meinberg radio clock
3.7.2. Configuring time zone and daylight saving
To adjust computer clock and MicroSCADA applications to daylight saving time, follow the instructions given below:
1. Open Control Panel > Date and Time.
2. Click the Time Zone tab to change your zone.
* To perform the above action, click the drop-down arrow, and then select your current zone.
3. Select Automatically adjust clock for daylight saving changes.
4. Open Monitor Pro > Tools > Options.
5. Click Daylight Settings > Automatically adjust applications for daylight saving changes.
3.7.3. Time zone and daylight saving history
The base system maintains the history of time zone and daylight saving time rules obeyed in the site. The history is found in file SYS_TIME.PAR located in folder \SC
\SYS\ACTIVE\SYS_.
The history is used for two purposes:
* To display old time tags correctly
The site may have been moved from a time zone to another, or daylight saving time may have been applied differently in the past. As the base system stores the time tags in UTC time, the history is needed to correctly convert the tags to the local time of the moment of event.
* To time future actions correctly
The base system transfers the current time zone and daylight saving information from the operating system at each system startup and maintains the history automatically. However, there are a few cases, where you might want to edit the history explicitly:
* Time zone and/or daylight saving time settings are changed and it is not acceptable to shut down and restart the system for this reason.
* Prior to SYS 500 revision 8.4.4, the time tags were stored in local time. If a revision 8.4.3 application or older is upgraded and the time zone and/or daylight saving time settings have been changed during the age of the application, the old settings should be copied to the base system to display old time tags correctly.
* If it is known that time zone and/or daylight saving time settings are to be changed in the future, it is useful to transfer the new settings to the base system in advance. Then, the base system is able to correctly time the once-only time channels scheduled after the coming change of settings. In addition, other local/
UTC time conversions of future time tags are done correctly.
The explicit editing of SYS_TIME.PAR is done with SCIL function TIME_ZONE_RULES, refer to the Programming Language SCIL manual.
As there are some complications of local/UTC time handling, it is recommended that engineering of a new application is done in a PC that uses the time zone and daylight saving time settings of the target site.
3.7.4. Configuring representation of dates
There are two places to configure representation of time and date in Monitor Pro:
* TF-attribute
With TF-attribute the following conventions are available:
yy-mm-dd hh:mm:ss, when TF=0 dd-mm-yy hh:mm:ss, when TF= 1
The default value for time format can be configured in SYS_BASCON.COM, where node for base system is created.
Extract from SYS_BASCON.COM
#CREATE SYS:B =
List(-SA = 209,- ;Station address of base system ND = 9,- ;Node number of base system TM = "SYS",- ;Time Master, SYS or APL TR = "LOCAL",- ;Time Reference, LOCAL or UTC TF = 1,- ; Time Format
Like Alarm list and Event list, Monitor Pro applications follow time format defined by TF.
* Initialization file FRAMEWINDOW.INI
FRAMEWINDOW.INI is a user specific file and it is located in directory \sc\apl\' apl name'\PAR\'user name'. The representation order of time and date can be configured in DAYFORMAT section of the above mentioned file. The configuration applies for the Monitor Pro status bar. To learn more about this configuration, see the example given below:
[DAYFORMAT]
FreeDateTimeField=%Y-%m-%d %H:%M:%S
The default represention style in status bar follows the TF-attribute setting. If DAYFORMAT is defined it will be used.
A list of all possible options for configuring DAYFORMAT is given below:
* Year
%y, Year without century
%Y, Year with century
* Month
%b, Abbreviated month name
%B, Full month name
%m, Month as number (01– 12)
* Week
%W, Week of year as decimal number, with Monday as first day of week (00 – 53)
%U, Week of year as decimal number, with Sunday as first day of week (00– 53)
* Day
%d, Day of month as number (01 – 31)
%j, Day of year as number (001– 366)
%w, Day of week as number (0 – 6; Sunday is 0)
%a, Abbreviated weekday name
%A, Full weekday name
* Hour
%H, Hour in 24-hour format (00 – 23)
%I, Hour in 12-hour format (01– 12)
%p, Current locale's A.M./P.M. indicator for 12-hour clock
* Minute
%M, Minute as number (00– 59)
* Second
%S, Second as number (00– 59)
* Misc
%c, Date and time representation appropriate for locale
%x, Date representation for current locale
%X, Time representation for current locale
%z, %Z, Either the time-zone name or time zone abbreviation, depending on registry settings; no characters if time zone is unknown