Frequently asked questions

FA280020

28 September 2021

Overview

The SCADAPack E RTU can operate using UTC or Standard Time in the RTU Real Time Clock. When using the DNP3 protocol, UTC time is the recommended industry practice. When using UTC time, some logic applications may require local time and/or daylight savings time. The SCADAPack E RTU has the ability to display local time and control if daylight savings time needs to be applied

SCADAPack E Configuration

UTC & Standard Time

When UTC Time is set in the SCADAPack E RTU real time clock, the Time Offset from UTC system point (float system point 63201) should be set appropriately (as per the installation of the RTU). Where Standard Time is set in the RTU real time clock, the Time Offset from UTC should be set to zero.

The Time Offsett from UTC system point 63201 can be found on the General -> Controller Settings property page of SCADAPack E Configurator.

Summer Time

If summer time activities are required, it is not necessary to adjust the RTU Real Time Clock. Rather, the Time Zone Modifier system point (binary system point 50302) can be activated. This system point is also known as Apply Daylight Savings point. Setting this point is the responsibility of the SCADA Master or a combination of information from the SCADA Master and a user-created logic program.

The Time Zone Modifier selects summer time on the RTU when the binary system point is active. The RTU immediately adjusts for summer time upon receiving a control message from the SCADA Master to set the point.

When Summer Time is selected, certain RTU facilities receive local information from the RTU based on Standard Time + 1.0 Hours. When summer time is not selected, these facilities receive standard time.

Example

In the example below the RTU is located in Ottawa, Canada. The date is September 30th, 2015 UTC time is 8:14pm. Daylight Savings time is enforced, thus binary point 50302 is enabled from the SCADA Host. The Configuration is set to have a UTC time offset of -5. The TIMEDATE block in SCADAPack Workbench CAM5 will return the local time values. DNP3 events are still generated using UTC time, the SCADA host is configured for UTC time, yet logic can execute using local time. The adjustment of daylight savings time is facilitated using binary output point 50302 twice a year.

Time Presentation

Except where noted below, RTU facilities use UTC or Standard time (e.g. RTU Real Time Clock, Trends, and DNP3 Time-stamps).

Summer Time (Daylight Savings) corrected time only affects RTU sub-systems that use Local Time. The following table indicates which SCADAPack E RTU facilities use Local times (UTC offset and Daylight Savings / Summer time adjusted) or UTC / Standard (Summer time independent) times.

RTU Facilities Using UTC or STANDARD Time (Independent of Summer Time	RTU Facilities Using LOCAL Time (Adjusted for UTC offset and Daylight Savings Time)
RTU Real Time Clock	Profiler Task
Trend sample time-stamps	ISaGRAF TIMEDATE Function Block
DNP3, IEC60870-5 protocol event time-stamps	ISaGRAF LOC_TIME Function Block
ISaGRAF OS_TIME Function	ISaGRAF DAY_TIME Function
Times shown in RTU diagnostics

More Examples

Example 1 – SCADAPack E RTU clock set to UTC time, Daylight Savings not applied
UTC Time = 11:15:10.5 Time Offset to UTC = 10.0 hours Apply Daylight Savings = NO · Trend samples, DNP3 events, RTU diagnostics indicate 11:15:10.5 · ISaGRAF OS_TIME returns seconds since Jan 1, 1970 UTC · Profiler control time = 21:15:10.5 · ISaGRAF LOC_TIME & TIMEDATE function block indicates 21:15:10 · ISaGRAF DAY_TIME function indicates 21:15:10

Example 2 – SCADAPack E RTU clock set to UTC time, Daylight Savings applied
UTC Time = 11:15:10.5 Time Offset to UTC = 10.0 hours Apply Daylight Savings = YES · Trend samples, DNP3 events, RTU diagnostics indicate 11:15:10.5 · ISaGRAF OS_TIME function returns seconds since Jan 1, 1970 UTC · Profiler control time = 22:15:10.5 · ISaGRAF LOC_TIME & TIMEDATE function block indicates 22:15:10 · ISaGRAF DAY_TIME function indicates 22:15:10

Example 3 – SCADAPack E RTU clock set to Standard time, Daylight Savings not applied
RTU Time = 11:15:10.5 Time Offset to UTC = 0.0 hours Apply Daylight Savings = NO · Trend samples, DNP3 events, RTU diagnostics indicate 11:15:10.5 · ISaGRAF OS_TIME returns seconds to 11:15:10 since Jan 1, 1970 standard time · Profiler control time = 11:15:10.5 · ISaGRAF LOC_TIME & TIMEDATE function block indicates 11:15:10 · ISaGRAF DAY_TIME function indicates 11:15:10

Example 4 – SCADAPack E RTU clock set to Standard time, Daylight Savings applied
RTU Time = 11:15:10.5 Time Offset to UTC = 0.0 hours Apply Daylight Savings = YES · Trend samples, DNP3 events, RTU diagnostics indicate 11:15:10.5 · ISaGRAF OS_TIME returns seconds to 11:15:10 since Jan 1, 1970 standard time · Profiler control time = 12:15:10.5 · ISaGRAF LOC_TIME & TIMEDATE function block indicates 12:15:10 · ISaGRAF DAY_TIME function indicates 12:15:10