dataTaker - Data Loggers, Powerful and Flexible Data Acquisition & Data Logging Systems

The Real Time Clock

The dataTaker real time clock keeps the Day Number or Date in three formats, and the Time of day in three formats. The real time clock is used for triggering Schedules, for date and time stamping data acquisition, Alarms, System Timers, and for other system timing functions.

The formats for date and time described below only apply if the Free Format data mode selected (/h).

Day Formats

The day can be returned as the Day Number or Date in one of three formats. The format is specified by the Parameter31 command as follows

P31=0 selects the Day Number format, for example                    Day 5316
P31=1 selects the DD/MM/YYYY format, for example                 Date 23/07/2003

This is the default date format for 50 Hz line frequency operation, as determined by the line frequency setting of the DIP switch.

P31=2 selects the MM/DD/YYYY format, for example                 Date 07/23/2003

This is the default date format for 60 Hz line frequency operation, as determined by the line frequency setting of the DIP switch.

Time Formats

The Time of day can be returned in one of three formats, which is specified by the Parameter39 command as follows

P39=0 (default) selects the hh:mm:ss format, for example             Time 15:30:45

The character used to separate the hours, minutes and seconds can be defined as any ASCII character by the Parameter40 command. The default is ASCII 58 (:)

P39=1 selects the seconds from midnight format, for example       Time 23465 Secs
P39=2 selects the decimal hours format, for example                  Time 22.38522 Hours

Decimal Day

The dataTaker also has a Decimal Day format for time, which is a decimal value for which the whole number is the day number, and the fraction is the time of day expressed as a fraction of a day.

The Decimal Day is returned by reading the System Variable 12 by the command

12SV

which returns the decimal day as follows

12SV  1269.9

If the global  maximum number of significant digits is increased to say 7 using the Parameter32=7 command, then greater resolution for the fraction of the day can be obtained as follows

12SV  1269.953

Reading 12SV(FF0) returns the day number only.

Setting the Day or Date

The Day Number or Date is set in the format which is defined by the current setting of the Parameter31 command as follows

If P31=0 then the Day Number is set by the command

D=ddddd

If P31=1 then the Date is set by the command

D=dd/mm/yyyy

If P31=2 then the Date is set by the command

D=mm/dd/yyyy

where

ddddd          is the day number in the range 0 ñ 49,700
dd               is the day of the month in the range 1 ñ 31
mm              is the month in the range 1 ñ 12
yyyy             is the year in the range 1989 ñ 2060

In the dataTaker the Date is referenced from 1/1/1989, which is equivalent to Day Number 0.

Using DeTransfer, the day number or date are set in the different formats by the commands for example

D=5316
D=23/7/2003
D=7/23/2003

DeTransfer also has a special command for setting the date of the dataTaker

D=\d

which sets the date according to the clock of the host computer. Note : The Date format for the dataTaker must be the same as the Date format set in the Regional Options applet of the Windows Control Panel.

There is no requirement to set the date format in DeLogger ñ DeLogger handles this automatically. The dataTaker date is set by selecting Set Date/Time on the dataTaker menu, or by clicking the Set Date and Time toolbar button.

 

Setting the Time

The Time is set in the format which is defined by the current setting of the Parameter39 and Parameter40 commands as follows

If Parameter39=0 then Time is set in the hh mm ss format, using the separator defined by Parameter40

T=hh:mm:ss

There are a number of variations to this time set command as follows

T=hh           sets clock to hh:00:00
T=:mm        sets clock to 00:mm:00
T=::ss         sets clock to 00:00:ss
T=hh::ss      sets clock to hh:00:ss

where

hh                is the hours
mm              is the minutes
ss                is the seconds
:                  is the separator, declared by Parameter40

Using DeTransfer, the Time is set in hh:mm:ss format by the commands for example

T=15:45:30
T=10
T=::30

DeTransfer also has a special command for setting the time of the dataTaker

T=\t

which sets the time according to the clock of the host computer. Note : The Time format for the dataTaker must be set to HH:MM:SS to match the Windows time format.

If Parameter39=1 then Time must be set in seconds from midnight by the command

T=sssss

where

sssss            is the number of seconds, 0 ñ 86,400

Using DeTransfer, the Time is set in seconds format by the commands for example

T=0
T=46200

If Parameter39=2 then Time must be set in decimal hours by the command

T=hh.hhhhh

where

hh.hhhhh       is the time in decimal hours, 0.000277 hours = 1 second

Using DeTransfer, the Time is set in decimal hours format by the commands for example

T=0.0
T=12.50833

There is no requirement to set the time format in DeLogger ñ DeLogger handles this automatically. The dataTaker time is set by selecting Set Date/Time on the dataTaker menu, or by clicking the Set Date and Time toolbar button.

 

 

Reading The Real Time Clock

The Day Number or Date and the Time 'channels' of the real time clock are treated in the same manner as other input channels. The date and the time of scanning input channels can be returned with the scan data by including the Day or Date and the Time channels in the schedule lists.

The Day or Date and the Time are specified by the identifiers

Day Number or Date

D

Time

T

Using DeTransfer, the date and time of scanning input channels are included with the input channel data by the commands for example

BEGIN
 RA10M
  D T
 
 1..6V
  8..10TN
  1..2DS
  3HSC(R)
END

which returns the Day Number or Date and Time at which each scan with the input channel data.

The date and time information is actually formatted by the dataTaker as these are transmitted to the host computer. Therefore if you are using DeTransfer, the format of date and time in logged data can be changed after data collection, before the logged data is returned to the computer.

Using DeLogger, the date and time of scanning input channels is included in the returned data by including the Date and Time channels in the program in the Program Builder as follows

 

 

Automatic Date and Time Recording

The dataTaker automatically records the date and time that Schedules are run to scan input channels, perform calculations, etc, even if the original Schedule does not include the D and T channels.

The return of this automatically recorded date with the logged or real time data is determined by the Date Switch command as follows

/D     Enable return of automatically recorded date
/d      Disable return of automatically recorded date (Default)

The Date Switch defaults to /d when the dataTaker is powered up, hardware reset or executes a RESET command.

The return of this automatically recorded time with the logged or real time data is determined by the Time Switch command as follows

/T  Enable return of automatically recorded time
/t   Disable return of automatically recorded time (Default)

The Time Switch defaults to /t when the dataTaker is powered up, hardware reset or executes a RESET command.

When the Date Switch and the Time Switch are enabled, then the date and time of data acquisition is returned at the start of the data block for each Schedule in the program. If date and time channels are included explicitly in the schedule lists, and the Date and Time Switches disabled (/d /t), then the date and time are returned in the position that they were placed in the schedule list relative to other channels.

DeLogger does not use the Date and Time Switches ñ DeLogger uses the Fixed Format mode for all data, which includes date and time stamps.

Assigning Date and Time to Channel Variables

The date and time can be assigned to Channel Variables whenever the real time clock is read in Schedules, and used in calculations, as test inputs and setpoints for alarms, etc.

The Day Number, Date and Time are assigned to Channel Variables by specifying the Channel Variable as a channel option, in the same manner as assigning data from input channels to Channel Variables (see Section III ñ Channel Variables and Calculations).

Using DeTransfer, assigning the date and time to Channel Variables is illustrated by the following examples

D(=1CV)
T(=2CV)

Irrespective of the current formats defined for date and time, the assignment of these to channel variables is fixed as follows

date is assigned as the number of days since 01/01/1989, which is day number 0

time is assigned as the number of seconds since last midnight

When these are read and assigned to a Channel Variable, the date and/or time is also returned to the host in the current format. This can be disabled by including the W or NR channel options in the command as follows

D(=1CV,W)
T(=2CV,NR)

Using DeLogger, the date and time can be assigned to Channel Variables in the Program Builder as follows

 

 

 

 

 

 

 

 

 

Date and Time in Alarms

The date and time can also be used in Alarms (see Section III ñ Alarms) to test for the arrival of a particular date or particular time. The date or time 'channel' are used as an input channel for an alarm, and are tested against setpoints.

The date setpoints must be entered in the format currently defined by Parameter31, and the time setpoints must be entered in the format currently defined by Parameter39 and Parameter40.

Using DeTransfer, alarms which test for a date or time are entered by the commands for example

ALARM1(D>28/07/2003)"Tomorrow becomes today"

ALARM2(T><10:30:00,16:30:00)"Time window open"

In the first example the alarm will become true at midnight, and remain true for the duration of the date.

In the second example the alarm will become true at 10:30:00, and remain true until16:30:00, each day.

Page Content


Home

Title and Waranty

Go to: Section 2 | Section 3

Section 1


Construction of the dataTaker 50

Construction of the dataTaker 500 600

Construction of the CEM

Getting Started

 

Section 2


Interfacing

Powering the dataTaker

Powering Sensors from the dataTaker

The Serial Interfaces

The RS232 COMMS Serial Interface

The NETWORK Interface

Analog Process

Connect Analog

Analog Chns

Measuring Low Level Voltages

Measuring High Level Voltages

Measuring Currents

Measuring 4-20mA Current Loops

Measuring Resistance

Measuring Frequency and Period

Measuring Analog Logic State

Measuring Temperature

Measuring Temperature with Thermocouples

Measuring Temperature with RTDs

Measuring Temperature with IC Temperature Sensors

Measuring Temperature with Thermistors

Measuring Bridges and Strain Gauges

Measuring Vibrating Wire Strain Gauges

The Digital Input Channels

Monitoring Digital State

The Low Speed Counters

The Phase Encoder Counter

The High Speed Counters

The Digital Output Channels

The Channel Expansion Module

Installing The Panel Mount Display

 

Section 3


Programming the dataTaker

Communication Protocols and Commands

Entering Commands and Programs

Format of Returned Data

Specifying Channels

The Analog Input Channels

The Digital Input Channels

The Counter Channels

The Digital Output Channels

The Real Time Clock

The Internal Channels

Channel Options

Schedules

Alarms

Scaling Data - Polynomials, Spans and Functions

CVs Calcs and Histogram

Logging Data to Memory

Programming from Memory Cards

STATUS RESET TEST

Switches and Parameters

Networking

Writing Programs

Keypad and Display

Error Mess Text

Appendix A - ASCII

Appendix B - ADC Timing