Introduction to the dataTaker

About This Manual

This Technical Reference Manual applies directly to Series 3 dataTaker 50, 500, 505, 515, 600, 605 and 615 model data loggers, which have firmware version 7.xx installed. The firmware version is returned in the first line of the TEST command.

The earlier Series 1 and Series 2 of the dataTaker data loggers are all very similar to the Series 3 models, provided that these loggers have the latest version firmware installed as follows:

Series 1 Firmware Version 4.02
Series 2 Firmware Version 5.00

Therefore this manual can also be used in support of these earlier version data loggers, and differences can be ascertained by comparison with your original Getting Started and Concise Manuals.

This manual is complimentary to the Getting Started with DT50, DT500 and DT600 Series dataTaker manual, and the Users Manual DT50, DT500, DT600 Series dataTaker Series 3, that are supplied with Series 3 loggers. This manual covers all of the dataTaker data loggers including:

dataTaker 50

dataTaker 500, dataTaker 505, dataTaker 515
- these data loggers will be referred to as the dataTaker 500 series loggers in this manual

dataTaker 600, dataTaker 605, dataTaker 615
- these data loggers will be referred to as the dataTaker 600 series loggers in this manual

Channel Expansion Modules (CEM-AD)
- for dataTaker 500 series loggers and dataTaker 600 series loggers

Panel Mount Display modules
- for dataTaker 50 and dataTaker 500 series loggers

Wherever dataTaker is used solely in this manual without reference to a model number, then the information pertains to all of the dataTaker models.

Since there are many common features for the dataTaker models 500, 505, 515, 600, 605 & 615, these models will be referred to throughout this manual as the 'dataTaker 500/600 series loggers', unless otherwise stated.

Introduction to the dataTaker

The dataTaker data loggers are microprocessor based intelligent data acquisition instruments able to monitor, record (log) data, and raise alarms for a wide variety of physical parameters including temperature, pressure, flow, counts, events, etc.

The key features of the dataTaker are accuracy, flexibility, low power consumption and optionally a large and removable data storage memory.

The dataTaker can be supervised from any host computer using companion software such as DeLogger or DeTransfer, or any generic terminal program such as Windows HyperTerminal or other freeware, shareware or commercial terminal programs. The dataTaker accepts instructions in ASCII text issued from the computer to configure the logger, to specify data acquisition, to control return and logging of data, to define testing and annunciation for alarms, to manage the digital output channels, etc. Analog and digital input signals are converted to data in ASCII text, suitable for reading directly into the host computer via the RS232 serial interface.

The dataTaker is intelligent such that when the logger has been programmed from the host computer, it is capable of operating off line acquiring data into memory for later recovery, all the while monitoring alarms and performing simple control functions.

The dataTaker 50 and dataTaker 500/600 series loggers share many common features and capabilities. The fundamental differences between these models are the number of channels supported, the ability to operate in a network, mechanical construction and the ability to support the optional Channel Expansion Modules.

The dataTaker 50 has 5 differential (double ended) or 10 single ended analog input channels, 5 digital input/output channels, and 3 high speed counters. The dataTaker 50 does not support the Channel Expansion Module.

In contrast the dataTaker 500/600 series loggers have 10 differential or 30 single ended analog input channels, 4 digital input/output channels, and 3 high speed counters. The dataTaker 500/600 series loggers support the Channel Expansion Module.

The dataTaker 600 series loggers also have a built in display. The dataTaker 50 and dataTaker 500 series loggers have the option of a separate Panel Mount Display module.

The analog to digital converter of the dataTaker data loggers has 15 bit plus sign bit resolution. This high degree of resolution allows the dataTaker to monitor very low level signals such as thermocouples and strain gauges with high accuracy and resolution.

Linearization and compensation for standard sensors such as thermocouples, RTDs, thermistors and solid state temperature sensors is automatically performed whenever these sensor types are monitored. Commands are also provided to allow user defined linearization for most sensor types that may be used with the dataTaker.

The dataTaker is supplied as a free standing module. The module is suitable for use directly on any laboratory bench, and can be mounted into virtually any type of enclosure suitable to the application.

Wall mounting industrial quality steel enclosures rated to the IP55 standard are available as optional enclosures. A weatherproof carry case rated to IP67 standard is also available for those applications where portability or remote siting is required.

The principal features and operation of the dataTaker data loggers is introduced below, and described in detail in the following chapters.

The dataTaker Features

The major features of the dataTaker data loggers and CEM-AD are summarized in the table below:

	*DT50*	*DT500*	*DT505*	*DT515*	*DT600*	*DT605*	*DT615*	*CEM-AD*
Analog Inputs Diff/SE	5/10	10/30	10/30	10/30	10/30	10/30	10/30	10/30
CMOS Multiplexed	ï	ï			ï
Relay Multiplexed			ï	ï		ï	ï	ï
Vibrating Wire Support				ï			ï
Digital I/O - State	5	4	4	4	4	4	4	20/10
Low Speed Counters	5	4	4	4	4	4	4
High Speed Counters	3	3	3	3	3	3	3
RS232 COMMS	ï	ï	ï	ï	ï	ï	ï
Max. COMMS baud rate	9600	9600	9600	9600	9600	9600	9600
RS232 electrically isolated	ï	ï	ï	ï	ï	ï	ï
Can be networked		ï	ï	ï	ï	ï	ï
Internal 1.2 AHr battery		ï	ï	ï	ï	ï	ï
Built in display					ï	ï	ï
Panel Mount Display	Option	Option	Option	Option
CEM Support		ï	ï	ï	ï	ï	ï

Communicating with the dataTaker

The dataTaker is operated in conjunction with a host computer, which is used to enter commands and programs to the logger, to process the data returned after input channels are scanned, to respond to alarms, and to directly manage output channels. The computer can either be running companion software such as DeLogger or DeTransfer, or any generic terminal program such as Windows HyperTerminal or other freeware, shareware or commercial terminal program.

The dataTaker has an RS232 serial interface for communicating with the host computer, either directly or via modems, and for outputting data to printers. This RS232 serial interface of the dataTaker is referred to as the RS232 COMMS interface.

All communications between the host computer and the dataTaker is in standard ASCII characters. There are no special communications formats or protocols used that require specific management by the host computer. However a protocol mode can be selected for noisy communication links.

The baud rate of the RS232 COMMS serial interface is set via DIP switches to 300, 1200, 2400, 4800 or 9600 baud all dataTaker loggers. The number of data bits and stop bits, and parity checking are permanently set to 8 data bits, 1 stop bit and no parity.

The communications link between the dataTaker and the host computer may be direct for distances of up to 100 metres (110 yards), or via simple line drivers for distances of up to 5000 metres (5500 yards), or via modems, radio and satellite links for longer distances.

The dataTaker 500/600 series loggers also have an RS485 serial interface for communications between loggers in a network. Up to 32 dataTaker 500/600 series loggers can be connected into a local network.

The RS485 serial interface of the dataTaker 500/600 series loggers is referred to as the NETWORK interface. Network communication via the NETWORK interface is permanently set to 1200 baud, and is fully error checked.

Modes of Operation and Networking

The dataTaker may be operated in one of a number of different modes, depending on the availability of computer time, the data volume, and the location and number of sensors.

The most common mode of operation is where the dataTaker is periodically supervised by a permanently connected computer. Scanning of input channels and data collection can be progressively varied, the resultant data can be managed by the computer in real time, active alarms can be responded to directly in a reactive or corrective manner, and digital output channels can be managed directly. DeLogger and DeTransfer/DePlot are suited to this mode of operation where acquired data is to be progressively displayed, graphed and archived.

The alternative mode of operation is where the dataTaker is initially programmed from a temporarily connected computer, and the logger is then left to scan input channels, log the data into the internal memory or memory card, and monitor and annunciate alarms, independently of the host computer. The data can be recovered from memory when the host computer is reconnected at a later time. DeLogger and DeTransfer/DePlot are also suited to this mode of operation.

The dataTaker 500/600 series loggers can also be used in a mode where up to 32 dataTakers are connected into a local or widely deployed network. The individual dataTakers within the network are linked via the RS485 NETWORK serial interfaces, and the host computer is connected to the RS232 COMMS serial interface of any logger in the network. This mode of operation generally requires a permanently connected host computer to supervise the individual loggers.

Other serial devices such as other computers, terminals, printers, or data storage devices may be connected to the RS232 COMMS serial interface of other loggers in the network, and accessed by the host via the network.

Supervising the dataTaker

Supervision of the dataTaker by the host computer may be periodic, partial or total, depending on the application, the volume of data acquired, and the management of alarms.

Commands which configure the dataTaker, specify the acquisition of data, define the testing and annunciation of alarms, manage the digital output channels, etc. are all entered directly from a host computer. Data resulting from the scanning of input channels can be returned to the computer as the channels are scanned.

However once the dataTaker is programmed, the computer can be disconnected and the logger left to operate independently. The scan data can be stored in the internal data memory of the dataTaker, or into a memory card, and returned to the host computer at a later time. The host computer can be disconnected during the period of data logging, and the data can be recovered when the host computer is later reconnected.

Host Computer Software

The software requirement for the host computer depends on the nature of the task to be performed.

The simplest form of host computer software is any terminal program that supports an RS232 port of the computer, and can be used to supervise the dataTaker by sending commands as they are typed, and displays and stores raw data as it is received from the logger. A terminal program does not support particular management of data, responses to alarms, real time commanding of the logger, etc.

The Windows HyperTerminal program, or any freeware, shareware or commercial terminal program can be used to supervise a dataTaker logger in an emergency if proprietary software is unavailable.

DeTransfer software has been developed specifically for the dataTaker. DeTransfer is essentially a text editor and a terminal, used for creating and sending programs to the dataTaker, and for receiving, displaying and storing raw data from the dataTaker. The DePlot software is used to plot data collected by DeTransfer either in real time or from memory. DeTransfer and DePlot are usually supplied with the dataTaker data loggers.

When a computer is used as the host, then a variety of software packages can be used to supervise the dataTaker, to manage and present the data, to respond to alarms, and to directly manage digital output channels, etc.

By contrast, the DeLogger software supplied with the dataTaker loggers provides for much more supervision of the logger, including graphical programming interface, displaying data as raw data, as charts, as meters, and as tables or forms, responding to alarm states, storing data, etc. In addition applications developed in DeLogger can be automated to make repetitive use simpler. Consult your DeLogger manuals for details of use of this software.

There are also some special purpose application software packages that can be used for supervising the dataTaker, provided appropriate drivers are available. These include National Instrumentís LabView, CI Technologiesí CiTech, DasyLab, Adroit, etc.

Because all data is returned from the dataTaker in standard ASCII character text, the data can also be imported into text editors, word processors, spreadsheets, graphics packages, etc.

dataTaker Input and Output Channels

The dataTaker 50 has 5 differential (double ended) analog input channels. These input channels can also be used as 10 single ended analog input channels, or in any mix of differential and single ended channels.

The dataTaker 500/600 series loggers have 10 differential analog input channels. These input channels can also be used as 30 single ended analog input channels, or in any mix of differential and single ended channels.

The analog to digital converter (ADC) of the dataTaker recalibrates automatically, based on drift of the internal zero reference voltage. Autocalibration corrects for errors due to circuit aging, and to temperature drifts in the measurement circuits.

The ADC of the dataTaker is also auto-ranging, and automatically changes range as follows

the dataTaker 50, 500 and 600 all have a solid state multiplexer for the analog input channels, and autorange over three range decades of ±25.000 mV,
±250.00 mV and ±2500.0 mV.

the dataTaker 505, 515, 605 and 615 all have a relay multiplexer for the analog input channels, and autorange over three low range decades of ±25.000 mV, ±250.00 mV, and ±2500.0 mV when the internal attenuators are deselected, and autorange over three high range decades of ±7.000 V, ± 70.00 V and
±100.0 Volts when the internal attenuators are selected.

The conversion ranges for analog input signals do not need to be specified when programming the logger. Only the channel numbers which are to be scanned, the type of input on each channel (voltage, current, frequency, resistance, thermocouple, RTD, etc.) and the interval between scans, needs to be specified in scan commands.

The dataTaker 50 also has 5 bi-directional digital channels, which can be used as digital inputs or digital outputs. The dataTaker 500/600 series loggers have 4 bi-directional digital channels, which can be used as digital inputs or digital outputs.

The digital input channels of the dataTaker can be used to monitor logic states or contact closures, for low speed counting and for event detection.

The digital output channels of the dataTaker are open collector TTL / CMOS compatible logic outputs, which can drive relays and logic circuits directly.

All of the dataTakers also have 3 high speed counters, capable of operating at 1 KHz or 1 MHz.

Channel Expansion Modules (CEM-AD)

The channel capacity of the dataTaker 500/600 series loggers can be expanded by adding Channel Expansion Modules (CEM-AD). The dataTaker 500/600 series loggers can support 1 or 2 Channel Expansion Modules (CEM-AD) connected in a daisy chain with a total cable length not exceeding 2 metres (6 feet) in length.

The Channel Expansion Modules (CEM-AD) have 10 differential analog input channels, which can also be used as 30 single ended analog input channels, or in any mix. The Channel Expansion Module (CEM-AD) has the same input channel specification and sensor support as the dataTaker to which it is connected.

The Channel Expansion Modules (CEM-AD) also have 20 digital input channels for state monitoring, and 10 digital outputs configured as 5 relay outputs and 5 open collector TTL/CMOS compatible outputs. The Channel Expansion Module (CEM-AD) does not support counting.

Reading Input Channels

The scanning of the analog and digital input channels can be at regular intervals of time from 1 second to months, or in response to poll requests by the host computer, or in response to events occurring on the digital input channels or high speed counters.

Up to 7 scan commands for scanning input channels can operate simultaneously. Input channels can be scanned such that all data is returned, or scanned over a period of time and the average, standard deviation, minimum, maximum and integral data only is returned for the period.

The input channel data may be returned either in terms of the base electrical units of the transducers being monitored, or in terms of the actual physical quantities which the transducers are sensing. The dataTaker has inbuilt linearization for thermocouples, RTDs, solid state temperature sensors, thermistors and strain gauges, and has facilities for declaring calibration or linearization functions for other transducer types.

All signal input and output lines connect to the dataTaker and Channel Expansion Module (CEM-AD) via removable screw terminals.

Real Time Clock

The dataTaker incorporates a real time clock which keeps the time of day in HH:MM:SS, decimal hours and seconds formats, and keeps the date as day number in DDDDD format, or date in DD/MM/YY, MM/DD/YY and decimal day formats.

The dataTaker real time clock has a resolution of 1 second, and an accuracy of 2 seconds per day. The clock is battery backed, and will maintain date and time when the dataTaker is powered off.

The real time clock is used for many purposes including to initiate repeated time based scanning of input channels, for raising alarms as a function of time, and to timestamp and datestamp data from the input channels scanned.

There are also 4 internal system timers for use with the alarms functions.

Data Logging

The dataTaker has internal battery backed SRAM data memory, which can store approximately 166,500 readings (Series 1 and Series 2 loggers have smaller memory capacity). All data is logged with full precision over the range of ±1.0e-18 to ±1.0e18. Data is logged serially in the data memory, which may be defined to function either as a stop when full stack, or as a circular buffer where the newest data overwrites the oldest data after memory fills.

The data logging capacity of the dataTaker can be increased using plug in PC-Card or PCMCIA standard SRAM memory cards. These memory cards can be removed from the dataTaker at any time, and the data logged onto the card can be unloaded elsewhere either using another dataTaker, or a dataTaker MCI-04 Memory Card Reader, or by inserting the memory card into the PC-Card slot of some Notebook computers (this will depend on support provided by the computer manufacturer, and the particular version of Windows software used). While the memory card is removed, current data logging continues into the internal data memory.

The memory cards are available with the following memory capacities

512 Kbyte, stores approx 173,750 readings

1 Mbyte, stores approx 347,500 readings

2 Mbyte, stores approx 695,000 readings

4 Mbyte, stores approx 1,390,000 readings

Stored data is unloaded from the internal data memory and memory cards in the order of oldest data first.

Programming the dataTaker

The dataTaker is programmed using simple English-like commands. The individual commands are combined together to form command lines to program the data logger for particular tasks.

The different commands provide for

scanning of up to five different groups of selected analog and digital input channels

scanning a group of input channels in response to poll requests by the host computer

scanning up to four groups of input channels, each at a different time interval, or in response to digital events or counter events

conditionally scanning groups of input channels while nominated digital input channels are high or true

determining the average, the standard deviation, the minimum, the maximum and the integral readings for selected groups of input channels

inspection of input channels at any time without disrupting other scan commands in progress

performing calculations on the raw data from input channels

returning acquired data to the host computer in real time

storing acquired data in the internal data memory or memory cards, in stack or circular buffer mode

returning data from the data storage memory or memory cards

defining the format of returned data

setting the state of digital output channels

defining alarm conditions and the method for annunciating or reporting those alarms.

setting system variables, channel variables and general system configuration.

local viewing of acquired data and some system information, and executing predefined tasks, from the Display Keypad module (where fitted).

The various commands for programming the dataTaker are briefly discussed in context in Section II of this manual, and are discussed in detail in Section III of this manual.