Theodor Friedrichs COMBILOG 1020 Hardware Manual

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COMBILOG 1020

Datalogger

Hardware Manual Version 3.09

Hardware Manual COMBILOG 1020

Issue: 03.11.2005

Technical data are subject to change!

Hardware Manual COMBILOG 1020

Copyrights: Operating instructions, manuals and software are

subject of copyright. Copying, duplication, translation, conversion into any electronic medium or any machine readable form, as a whole or in parts, is not permitted, with the exception of making a back-up copy of the software for saving purposes, insofar as this is technically feasible and is recommended by our company. Contraventions will lead to compensation.

Limitation of Liability: No liability is assumed by Theodor Friedrichs for damages and/or injury resulting from use of equipment supplied by this company. In no event will Theodor Friedrichs be liable for indirect or consequential damages whatsoever resulting from loss of use, data or profits arising out of connection with the use of performance of Theodor Friedrichs products. Theodor Friedrichs products are not designed, intended, or authorized for use as components and medical systems, or other applications indeed to support or sustain life, or for any other application in which the failure of the Theodor Friedrichs product(s) could create a situation where personal injury or death may occur. Any claims against Theodor Friedrichs in connection with the hardware and software products described in this manual can exclusively be based on the guarantee regulations. Any further claims are excluded, in particular Theodor Friedrichs does not give any guarantee as to the correctness of the contents of this manual. Changes are subject to alteration and can be executed any time without advanced notice.

Trade Marks: Without going into details, we want to point out the usage of indications and entered trade marks, in particular the indications and trade marks of Microsoft Corporation, International Business Machines Corporation and Intel Corporation.

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Hardware Manual COMBILOG 1020

CHAPTER SURVEY

Page

1 GENERAL PRELIMINARY REMARKS ..... 13

2 SYSTEM DESCRIPTION ......................... 15

3 INSTALLATION ...................................... 22

4 SIGNAL PROCESSING ........................... 32

5 FUNCTIONAL DESCRIPTION ................. 40

6 DISPLAY / MENU OPERATION ............... 67

7 DATA STORAGE .................................... 78

8 MASTER FUNCTION .............................. 84

9 INITIATION AND TEST ........................... 87

10 STRUCTURE OF THE BUS TOPOLOGY.. 89

11 COMMUNICATION................................ 103

12 SPECIFICATIONS ................................ 147

13 SIMPLIFIED DRAWINGS ...................... 154

APPENDIX.................................................... 155

Hardware Manual COMBILOG 1020

TABLE OF CONTENTS

Page

1 GENERAL PRELIMINARY REMARKS ..... 13

1.1 On This Manual......................................................................... 13

1.2 Important Notice........................................................................ 13

1.3 Contact for Inquiries.................................................................. 14

2 SYSTEM DESCRIPTION ......................... 15

2.1 System Overview ...................................................................... 15

2.2 Range of Application................................................................. 16

2.3 Features.................................................................................... 17

2.4 Configration Software ...............................................................21

3 INSTALLATION ...................................... 22

3.1 Mounting / Fixing....................................................................... 22

3.2 Protective System ..................................................................... 22

3.3 Ambient Temperature ............................................................... 23

3.4 Front panel / Pin Assignment.................................................... 23

3.5 Connection................................................................................ 25

3.6 Power Supply............................................................................ 26

3.7 Bus Connection......................................................................... 27

3.8 Sensor Connection ...................................................................29

3.9 Several Sensors at one Datalogger .......................................... 30

3.10 Module Jack..............................................................................30

Hardware Manual COMBILOG 1020

4 SIGNAL PROCESSING ........................... 32

4.1 Analog Inputs ........................................................................... 32

4.2 Digital Inputs/Outputs ............................................................... 32

4.3 Internal Reference Voltage, Offset- and Drift Correction.......... 34

4.4 Internal Processing................................................................... 35

4.5 Scan Rate and power consumption ......................................... 38

4.6 Signal Processing..................................................................... 39

5 FUNCTIONAL DESCRIPTION.................. 40

5.1 Analog Input Channel............................................................... 41

5.2 Digital Input Channel ................................................................ 51

5.3 Digital Output Channel ............................................................. 58

5.4 Arithmetic Channel ................................................................... 61

5.5 Setpoint Channel...................................................................... 65

5.6 Alarm Channel.......................................................................... 65

5.7 Threshold Values ..................................................................... 65

5.8 Error Handling .......................................................................... 66

6 DISPLAY / MENU OPERATION ............... 67

6.1 Display and Operation.............................................................. 67

6.2 Menu Items............................................................................... 67

Hardware Manual COMBILOG 1020

7 DATA STORAGE .................................... 78

7.1 General Remarks to Data Storage............................................ 78

7.2 Modes of Data Storage ............................................................. 78

7.3 Internal Data Storage................................................................ 79

7.4 External Data Storage with PCMCIA SRAM Card .................... 81

7.5 External Data Storage with PCMCIA Flash Card...................... 81

8 MASTER FUNCTION .............................. 84

8.1 Master function .........................................................................84

9 INITIATION AND TEST ........................... 87

9.1 Before Connecting the Device .................................................. 87

9.2 After Connecting the Device ..................................................... 87

9.3 Configuration of the Datalogger ................................................ 87

10 STRUCTURE OF THE BUS TOPOLOGY.. 89

10.1 Bus Interface.............................................................................90

10.2 Bus Structure ............................................................................ 91

10.3 Transmission Speed and Line Length ......................................92

10.4 Bus Cable ................................................................................. 93

10.5 Bus Plug.................................................................................... 94

10.6 Bus Termination........................................................................ 95

10.7 Shielding ................................................................................... 97

10.8 PC Bus Connection................................................................... 99

10.9 Potential Equalization ............................................................. 100

10.10 Adjustment of Address and Baud Rate................................... 100

Hardware Manual COMBILOG 1020

11 COMMUNICATION ................................ 103

11.1 Bus Interface .......................................................................... 103

11.2 Bus Protocol ........................................................................... 103

11.3 Data Format ........................................................................... 104

11.4 Output Format ........................................................................ 105

11.5 ASCII-Protocol........................................................................ 108

11.6 PROFIBUS-Protocol............................................................... 119

11.7 Instruction Set in the PROFIBUS-Protocol ............................. 124

11.8 MODBUS-Protocol ................................................................. 130

11.9 Sample Program .................................................................... 143

11.10 Autocall Function.................................................................... 144

11.11 Modem Connection ................................................................ 146

12 SPECIFICATIONS................................. 147

12.1 Power Supply ......................................................................... 147

12.2 Signal Inputs/Outputs ............................................................. 147

12.3 Signal Processing................................................................... 147

12.4 Analog Inputs (8 per Module) ................................................. 148

12.5 Digital Inputs/Outputs (6 per Module)..................................... 149

12.6 Interfaces................................................................................ 149

12.7 Operating Conditions.............................................................. 150

12.8 Electromagnetic Compatibility ................................................ 150

12.9 Shell ....................................................................................... 152

12.10 Circuit ..................................................................................... 152

12.11 Accessories / Notice for Orders.............................................. 152

Hardware Manual COMBILOG 1020

13 SIMPLIFIED DRAWINGS ...................... 154

13.1 Front View............................................................................... 154

13.2 Side View................................................................................ 154

APPENDIX.................................................... 155

A. Pinout Arrangements for Analog Sensors at the Datalogger . 155 B. Pinout Arrangements for Digital Sensors at the Datalogger .. 156 C. Pinout Arrangements for Analog Sensors of Th. Friedrichs... 157

D. Pinout Arrangements for digital Sensors of Th. Friedrichs ....158

E. Configuration table for the datalogger..................................... 159

F. Accuracy / Resolution / Noise / Linearity / Temp-Drift ............160

G. Algorithms for special meteorological parameters ..................163

H. Description of Short Real Format............................................ 167

I. Notes for installing configuration software COMBILOG.EXE.. 168

Hardware Manual COMBILOG 1020

1 GENERAL PRELIMINARY REMARKS

1.1 On This Manual

The manual contains all important information concerning the function, installation and initiation of the datalogger COMBILOG

1020.

The description of the configuration software for the COMBILOG- System is available as Online-Help within the configuration software COMBILOG.EXE.

1.2 Important Notice

Make sure to use the datalogger COMBILOG 1020 exclusively in accordance with the notices, technical data and operating conditions mentioned in this manual. In case of inexpert handling or wrong application possible disturbances, measuring errors, effects on or from other appliances and facilities as well as possible endangering of human lives or tangible assets cannot be excluded!

Therefore if you have not yet operated the datalogger COMBILOG 1020, you should first of all study this manual thoroughly. While initiating or operating the appliance or in case service is required always observe the notices given in this manual.

Hardware Manual COMBILOG 1020

Please note further that there are other special regulations to be observed in case of application in potentially explosive surroundings (EExe, EExi, ...). These, however are not subject of this manual, which only explains the general use of the datalogger COMBILOG 1020.

1.3 Contact for Inquiries

In case of inquiries concerning the datalogger COMBILOG 1020 please contact your local distributor or directly Theodor Friedrichs & Co. GmbH.

Hardware Manual COMBILOG 1020

2 SYSTEM DESCRIPTION

2.1 System Overview

The COMBILOG 1020 is a datalogger with compact design, combined with integrated LC-display and memory slot suitable for PCMCIA memory cards. This datalogger was developed for meteorological, hydrological and environmental measuring systems, but it is equally suitable for countless further applications in industrial production. The COMBILOG 1020 features high performance, compact design (SMD components), low power consumption and moderate price.

The datalogger is equipped with 8 analog and 6 digital measuring channels; further channels for numeric calculation may be configurated. Two serial interfaces, RS232 and RS485, are builtin, featuring communication via ASCII, PROFIBUS or MODBUS. Data storage is achieved by internal RAM or PCMCIA memory card, optionally. „SELECT“ switch and 2-line LCD on the front panel allow to enter or modify a number of different modes and functions, such as scan rate and averaging time, as well as offset or gain. The COMBILOG 1020 can easily be mounted on a 35 mm standard rail, using its „snap-in“ clamp, and is therefore suitable for control cabinet installation, or similar. Thanks to its low power consumption, battery supplied systems are possible, whereby the use of a solar panel enables any extension of measuring period. Especially for battery supplied systems the datalogger can be delivered with reduced internal processor clock. Please note, that in this case the performance may be reduced too.

Hardware Manual COMBILOG 1020

For applications like outdoor use there is a version with stainless steel housing available, as well as various other accessories. Configuring of the datalogger is accomplished by means of an easy to handle WINDOWS

98/ME/NT/2000/XP software.

2.2 Range of Application

As described under (2.1), the most varying measurement tasks can easily be accomplished by means of the COMBILOG 1020. Some typical applications are e.g. measurement of temperature via resistance thermometers (Pt100), operation with combined sensors with current- or voltage output (e.g. windspeed measurement with DC generator) or position measurement and weight measurement by displacement transducers and force transducers. With these applications the datalogger COMBILOG 1020 supports measuring methods with 2-, 3- and 4-wire technique. The signal processing required in accordance with the sensors used, such as gain, linearisation, offset correction etc. can be adjusted individually by software. An external amplifier is not required. The digital signal inputs can be used, for example, to connect switches, initiators, digit emitters and oscillators. Thus status indications can be collected and tasks like e.g. position measurings, displacement measurements, angular measurements, frequency measurements and timings can be carried out. Furthermore special 8-bit-graycode-transmitters can be connected. Special calculations of measured values are possible by arithmetic channels. In case the 8 analog and 6 digital inputs are not sufficiant, other modules can be connected to the datalogger via the RS485 bus. In this case the COMBILOG is used as a bus master to read the measured values from the slave modules.

Hardware Manual COMBILOG 1020

All data can be transmitted via the integrated RS485 communication interface to a subsequent control (PLC) or to a computer (PC). Up to 127 modules can be connected with the two-wire line over distances of several km. At the same time the communication interface features programming and configuring the individual application from a PC. If the datalogger COMBILOG 1020 is not integrated in a bus, an additional RS232-interface is available for the user. This interface allows only a point-to-point connection up to max. 20 m (65 feet), but all functions of the RS485-interface remain available. Furthermore the datalogger can send messages in case of user definable conditions automatically via modem or SMS. A configuration program is included (requires Microsoft WINDOWS 98,ME,NT,2000, XP).

2.3 Features

Function:

 Measurement inputs for all common types of sensors for I, U

and R.

 Several different sensors can be connected simultaneously  Measured values monitored by programmable thresholds  Detection of sensor errors  Detection of communication errors  Programmable error handling  Calculation of average values, minima, maxima, standard

deviation and other arithmetic functions

 256 kB RAM internal data storage, extendadble upto 8 MB

with PCMCIA SRAM card (max. 65536 datasets)

 linear Flash memory cards up to 16 MB

Hardware Manual COMBILOG 1020

Inputs and Outputs:

 8 analog inputs (for 2-, 3- and 4-wire connection)  6 digital inputs/outputs (I/O ports), configurable

Power Supply:

 Power supply: +10 ... +18 VDC  All connections protected against excess voltage, excess cur-

rent and reverse polarity

 Battery operation is possible due to low power consumption

Display and Operation:

 LED-status key for digital inputs/outputs  LED-status key for malfunction and operation (ERR / RUN)  LC-display (2

x 16 characters) and push-/turn knob for opera-

tion

Measured Value Processing:

 Linearization, scaling and conversion into physical units  Option to adjust, modify or reset the processing parameters

individually

 Master function to retrieve data from external modules  Programmable averaging  Automatic message transmission via modem or SMS  Non-volatile storage for program, parameters and data

Hardware Manual COMBILOG 1020

Configuration:

 Configurable with PC-software under

WINDOWS™ 98/ME/NT/2000/XP

 Menu-guided sensor selection in plain text  Free configuration of up to 32 channels  Data base for the most common sensors  Definition of user-specific sensors  Setting of type and principle of measurement  Display of pin assignment  Input of linearization  Alarm settings  Programmable error handling  Arithmetic combination of sensor channels  Configurable measuring rate and averaging interval  Configuration on file (offline-operation)  Configuration via bus (online-operation)

Programming:

 Loading of a new download program  Allocation of address and baud rate via bus  Password to save the configuration and the data memory  Synchronizing of date and time with the host PC

Communication:

 Integrated RS 485 and RS 232 communication interface  Autonomous function independent of subsequent systems  Definition of the transmission protocol (ASCII,PROFIBUS,

MODBUS (on request))

 Definition of the telegram format (baudrate and parity)  Definition of the output format (field length/decimals/unit)  Simple instruction set

Hardware Manual COMBILOG 1020

Shell:

 Compact structural shape  Attractive design  Fast mounting  Snap-on mounting on DIN rail 35 mm / 1.4 inch  Protection IP20  Plug-in screwed terminals  Module jack, ground connection

Innovations from software version 3.00:

 Extendable to 32 channels  Resistance measurement in 2-, 3- and 4 wire mode  Measurement of thermocouples  Master function for data exchange with other modules on the

same bus

 Use of SRAM cards for memory expansion  Baud rate up to 38,400 bps  2 versions:

Standard version with 20 MHz processor clock Low power version with 5 MHz processor clock

 Additional communication commands for memory manage-

ment and password protection

 Automatic report in case of programmable conditions via mo-

dem or SMS

 Selectable scan rate between 0.5 sec. and 60 min, averaging

interval between 1 s and 12 h

 Event controlled averaging interval

Hardware Manual COMBILOG 1020

2.4 Configration Software

The COMBILOG 1020 is delivered with a configuration software for MS WINDOWS 98/ME/NT/2000/XP. This software allows the individual configuration of the datalogger. Measuring channels are defined as variables in a variable table. Predefined sensors can be selected from the integrated database. The linearization of the sensor signals will be performed automatically. Additional sensors can be defined. Additional parameters like scan rate, averaging interval, data recording, error handling, automatic message generation, master function etc. are configurable. A password enables protection of the configuration and the stored data. Instantaneous measured values can be watched directly. In case a software update for the datalogger is necessary, the configuration program provides a download function, that sends the new program to the logger. Communication is supported via standard interface (RS232), telephone or GSM modem or TCP/IP protocol.

Example for a configuration:

Hardware Manual COMBILOG 1020

3 INSTALLATION

3.1 Mounting / Fixing

The datalogger COMBILOG 1020 has a snap-on mounting for installation on standard profile rails 35 mm (1.4 inch) according to DIN EN 50022.

Installation on the DIN rail is performed by means of the four straps on the rear side of the datalogger. First push the two straps on the bottom behind the notch of the DIN rail and then press the datalogger on the DIN rail until the two straps on the top snap in.

In order to take the datalogger off the DIN rail slide the module lateral off the rail or in case it is not possible lift the datalogger slightly so that the straps on the top get off the notch and the datalogger can be taken off easily by pulling.

Attention: Refer to protection earth hints in chapter 3.5!

3.2 Protective System

The datalogger has an IP20 protective system. For outdoor installations datalogger COMBILOG 1020 can be installed in a stainless steel shell type 9910, thus featuring IP65 standard.

Hardware Manual COMBILOG 1020

3.3 Ambient Temperature

The admissible ambient temperature for the datalogger COMBILOG 1020 is -30 °C to +60 °C. The admissible storage tempera-

ture is between -40°C and +85°C. Attention: For certain memory card types, differing temperature ranges have to be considered.

3.4 Front panel / Pin Assignment

The front panel of the datalogger COMBILOG 1020 shows following elements:

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7

A I N 6A I N 5A I N 4A I N 3A I N 2A I N 1

A N A L O G

SELECT

MEMORY CARD / PCMCIA

Display

2 x 16 Character

SUPPLY RS 485 RS 232

0.1 AM

21 34567 8 9

111213

Figure 3.1 Front panel

Hardware Manual COMBILOG 1020

Description of the Parts:

Number Description Number Description

1 LC-display

6 digital I/Os

2 Interface for memory card 9 Status-LEDs for digital I/Os

3 Voltage supply 10 Module jack connection

4 interface connection RS485 11 LED RUN (green)

5 PC interface RS232 12 LED ERR (red)

6 Press/rotary knob

8 analog inputs

7 Fuse 0.1 A M *

Table 3.1 Description of the parts on the front of the device

* Integrated multifuse from serial number 090323

Pin Assignment:

Terminal Assignment Terminal Assignment

+10..18V Voltage supply + I/O 1…6 Digital I/O 1…6

0V Voltage supply - 0 V Ground for digital I/Os

A RS485-bus interface A SOURCE Source output

B RS485-bus interface B In+ Analog input +

RX RS232 receive In- Analog input -

TX RS232 transmitt

AGND

Ground for analog input

COM RS232 ground

Table 3.2 Pin assignment

Hardware Manual COMBILOG 1020

3.5 Connection

 Connection: plug-in screw terminals  Nominal cross section: 1.5 mm² (0.02 square inch)

unifilar/fine-strand (AWG 16)

 Length of wire stripping : 6 mm (0.2 inch)  Alternatively available: LP-terminals (spring loaded)

(upon request)  Protection earth: M3 screw with toothed washer at

rear

side of housing

The best way to pull off the screw terminals is to use a small screwdriver, placed as a lever between terminal and the front of the datalogger.

Not more than 2 leads should be connected with one clamp. In this case the leads should have the same conductor cross section.

Note: Wire connection is only allowed during power off. Note: In order to avoid influences from noise on the sensor sig-

nals shielded wires should be used for the power supply, the bus connection and the signal lines. ATTENTION: Before final installation, a suitable protection earth cable with terminal has to be connected to the ground connector at the back of the datalogger. Assure that the toothed washer is firmly pressed into the housing surface.

Hardware Manual COMBILOG 1020

3.6 Power Supply

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7A I N 6A I N 5A I N 4A I N 3A I N 2A I N 1

A N A L O G

SELECT

MEMORY CARD / PCMCIA

Display

2 x 16 Character

SUPPLY RS 485 RS 232

0.1 AM

Versorgung

U+

U-

Figure 3.2 Connection of the distribution voltage

Voltage range

 +10 ... +18 VDC

Power input

 0.1 W typical (up to 1W maximum, depending on configura-

tion)

Internal protector (reversible)

 excess current 0.1 A M  excess voltage

supply

Hardware Manual COMBILOG 1020

Non-regulated DC voltage between +10 and +18 VDC is sufficient for the power supply of the datalogger COMBILOG 1020. The input is protected against excess voltage and current and against reverse polarity. The power consumption remains approximately constant over the total voltage range, due to the integrated switching controller.

Due to its low current consumption (max. 70 mA at 12 VDC) the datalogger can also be remote-fed via longer lines. Several dataloggers can be supplied parallel within the admissible voltage range, considering the voltage drop in the lines. The supply lines can also be installed in one common cable, together with the bus line, if required.

In order not to charge the datalogger’s supply voltage unnecessarily, a separate power supply for sensors with a large current requirement is recommended.

3.7 Bus Connection

In general the datalogger is connected to the bus by applying the signal leads A and B of the incoming bus cable and A' and B' of the outgoing bus cable together to one terminal on the module (figure 3.3).

Hardware Manual COMBILOG 1020

RS-485 Busverbindung

A B

A' B'

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7A I N 6A I N 5A I N 4A I N 3A I N 2A I N 1

A N A L O G

SELECT

MEMORY CARD / PCMCIA

Display

2 x 16 Character

SUPPLY RS 485 RS 232

0.1 AM

Figure 3.3 Connection of the datalogger to the bus

Alternatively the bus can also be connected by a "stub cable" as shown in figure 3.4.

Owing to the removable terminal, the bus connection to other dataloggers remains valid, even if one datalogger is replaced by another.

Note: When connecting the logger to the bus, the two bus interfaces A and B must not be interchanged.

Note: The stub cable should be as short as possible, not longer than 30 cm (12 inch).

RS-485

bus conne

tio

Hardware Manual COMBILOG 1020

RS-485 Busverbindung

A B

A' B'

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7A I N 6A I N 5A I N 4A I N 3A I N 2A I N 1

A N A L O G

SELECT

MEMORY CARD / PCMCIA

Display

2 x 16 Character

SUPPLY RS 485 RS 232

0.1 AM

Figure 3.4 Connection of the datalogger to the bus by a stub cable

3.8 Sensor Connection

The analog and digital signal inputs and outputs are wired according to measurement task, to the transducer (sensor) that is used, and to the number of connected sensors. The pinout arrangements for the various types of measurement are described in chapter 5. The respectively valid pin assignment is determined by means of the configuration software.

Since the digital outputs are "passive" the processing of external elements always requires an external current supply. In case of larger loads this should be independent of the datalogger supply.

RS-485

bus connectio

Hardware Manual COMBILOG 1020

At the connection of inductive loads a connection with a diode is required in order to prevent possible damages by induced voltage.

Following devices can be connected directly to the digital outputs: signallamps, small relays, switching relays for larger loads, acoustic signal installations, buzzer respectively beeper etc., as long as the connected loads are not exceeding the values described in the technical data chapter 12.

3.9 Several Sensors at one Datalogger

The datalogger COMBILOG 1020 can simultaneously receive and process sensor signals from several different sensors. As many sensors can be connected as there are analog and digital signal inputs and outputs available (14 sensors max.; 8 analog and 6 digital).

3.10 Module Jack

The datalogger COMBILOG 1020 has a bus connection facility on the left and on the right side of the housing, featuring interconnection of the 10…18 VDC supply and the bus signal, for several COMBILOG’s.

Hardware Manual COMBILOG 1020

This kind of bus connection and of power supply is particularly advantageous if several dataloggers are mounted on one common profile rail side by side. In this case the connection via the terminals can be dropped, except for one module.

Note: It is necessary to take care that the current at the Module Jack is not higher than permitted. Thus, the power supply preferably should be led to the centre of the module line. For the same reason, it is not allowed to connect more than 6 dataloggers via the Module Jacks in one line.

A I N 2A I N 1

MEMORY CARD / PCMCIA

Display

2 x 16 Character

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7A I N 6A I N 5A I N 4A I N 3A I N 2A I N 1

A N A L O G

SELECT

MEMORY CARD / PCMCIA

Display

2 x 16 Character

SUPPLY RS 485 RS 232

0.1 AM

Modul-SchnellverbinderTragschiene 35 mm

U+ U-

ICM 100

RS-485 Busverbindung

Versorgung

Figure 3.5 Connection of two COMBILOG 1020 with Module Jacks

suppl

RS-485 bus connection

DIN-rail 35 mm (1.4 inch)

Hardware Manual COMBILOG 1020

4 SIGNAL PROCESSING

The datalogger COMBILOG 1020 has eight analog inputs and six digital inputs/outputs. Several different sensor signals as well as digital inputs and digital output signals can be connected and processed simultaneously.

4.1 Analog Inputs

The analog inputs serve to collect sensor signals, or to acquire control values respectively. They are particularly designed to measure voltages, currents and resistances.

There are 8 equal analog inputs, each input can be configured individually.

Note: Overloads of more than ± 10 VDC will lead to false measuring results in the according analog input channel. Overloads of more than ± 15 VDC will also have influence on the measuring accuracy of the other input channels!

4.2 Digital Inputs/Outputs

The six digital inputs/outputs of the datalogger can be configured

- independent of each other - as inputs or as outputs. The current status (in/out) is signalized by one LED each.

Hardware Manual COMBILOG 1020

As inputs the I/Os can be used for collecting feed-back signals, for measuring frequencies, as counters or for receiving special serial 8-bit-graycode signals. Status information can be issued by the outputs. Thereby host-controlled or process-controlled status outputs are possible.

The digital inputs have an excess voltage protection (transil diodes), with nominal threshold 18 V. Input voltages between

3.5 VDC and 18 DC are interpreted as logic LOW ("0"), input voltages lower than 1.0 V as logic HIGH ("1"). The maximum input current is 1.5 mA.

+ 3,5 V

+ 1,0 V

0 V

low high (1)

high low (0)

signal level logic level

Figure 4.1 Definition of signal levels and logic levels

The outputs are open-collector type with a maximum voltage of 18 VDC and a maximum current of 100 mA.

Hardware Manual COMBILOG 1020

4.3 Internal Reference Voltage, Offset- and Drift Correction

An internal reference voltage serves to adjust the entire analog signal processing automatically. Especially for measurement of extreme low voltages, currents and resistances, the configuration software features an additional compensation of temperature drift. With current- and voltage measurement, this is realized by an internal offset measurement. The measured offset is subsequently applied to correct the measured values. For Maximum accuracy with current measurement (temperature drift less than 25 ppm/K) it is recommended to accomplish the measurement via an external shunt with a correspondingly low temperature coefficient (< 5 ppm/K). For this purpose, the input channel has to be configured as a voltage input. For resistance measurement, a drift correction requires an additional input channel which has to be equipped with a suitable reference resistance. This resistance should have a low temperature coefficient (< 5 ppm/K). In the configuration table, this channel has to be defined as a reference channel with resistance input for drift correction, whereby the nominal value of this resistance (at 20°C) has to be indicated. Using the above described methods, the analog inputs can almost completely be kept free from temperature drift.

Hardware Manual COMBILOG 1020

4.4 Internal Processing

Next to collecting the analog input signals, the analog multiplexer at the input of the circuit collects the internal reference voltage. All these values are then transmitted to the programmable amplifier PGA, where the signals are amplified according to the kind and type of the connected sensors and then supplied to the A/D converter.

The A/D converter digitalises all incoming signals with a definition of 16 bit and at a rate that can be preset for the module by the user. The Sigma-Delta-procedure used for the A/D-convertion guarantees a high accuracy and a high linearization. The A/Dconverter processes an integrated amplifier with the amplifier stages of 1, 2, 4, 8, 16, 32 and 64. For very small signals, the module switches to an additional amplifier with amplifier stages of 100, 200, 400, 800 and 3200. The amplification in alignment with the accuracy and resolution of the calculated measuring values results from the selection of the measuring range which will be configured by assistance of the configuration software.

This software also enables use of a low pass filter, depending on the mains frequency (selectable between 10 and 400 Hz).

The microprocessor µP now edits the measuring signal in digital form. First the processor linearises and scales the signal and holds it ready for transmission via bus in programmable units. Further the processor monitors the measured values for excess of freely programmable threshold values. Thus a monitoring of failure or breaking of the sensing element or short-circuit can also be realised. The datalogger can be activated - by means of appropriate configuration - to provide a corresponding signal at the digital I/O in case of alarm. The digital I/Os are directly addressed and monitored respectively by the microprocessor µP.

Hardware Manual COMBILOG 1020

Hereafter an arithmetical averaging of the values is carried out. The average interval is the same for each channel and is adjustable in steps of 1, 2, 3, 4, 5, 10, 15, 20 and 30 seconds, 1, 2, 3, 4, 5,10, 15, 20, 30 minutes,resp. 1, 2, 3, 4, 6, 8 and 12 hours. The calculated values are finally stored in the memory. The special user program, the data for configuration, linearization and scaling etc. that are required by the processor µP for all tasks are retentively stored in a Flash EPROM. The timing control of the data processing is realised by an internal real time clock buffered by Gold cap capacitor.

Hardware Manual COMBILOG 1020

µP

Analog

Multiplexer

0 V

+10..18V

In -

In +

SOURCE

AGND

RS-485

Interface

Digital I/O

+12 V

5 V

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

In -

In +

SOURCE

AGND

A/D

Converter

LED RUN

LED ERR

SELECT

Display

RTC

Treiber

MEMORY CARD / PCMCIA

-12 V

RS-232

Interface

COM

0 V

I/O 1

0 V

I/O 2

I/O 3

I/O 4

0 V

I/O 5

0 V

I/O 6

0 V

Flash

EEPROM

RAM

Vpp

x100

Reference

64k x 8

256k x 8

Figure 4.2 block diagram of the datalogger COMBILOG 1020

Hardware Manual COMBILOG 1020

4.5 Scan Rate and power consumption

The A/D-converter digitalizes every signal at a rate that can be preset by the user. The scan rate can be selected between 0.5 sec. and 1 hour. In this selected time period all configured channels are scanned and processed correspondingly. The power consumption of the datalogger COMBILOG 1020 depends on this scan rate. Between the measuring cycles the datalogger will be set into a so-called “Sleep-Mode“. During this mode the datalogger needs only about 5 mW. The average current consumption over a longer time period will be accordingly:

filter number of used scan rate

analog inputs 1 sec 10 sec 60 sec

1 20 mA 6.5 mA 5.3 mA 2 25 mA 7.0 mA 5.3 mA 3 30 mA 7.5 mA 5.4 mA

50 / 60 Hz 4 35 mA 8.0 mA 5.5 mA

5 40 mA 8.5 mA 5.6 mA 6 45 mA 9.0 mA 5.7 mA 7 50 mA 9.5 mA 5.8 mA 8 55 mA 10.0 mA 5.8 mA

1 16.3 mA 6.1 mA 5.2 mA 2 17.5 mA 6.3 mA 5.2 mA 3 18.8 mA 6.4 mA 5.2 mA

200 Hz 4 20.0 mA 6.5 mA 5.3 mA

Accu-operation 5 21.3 mA 6.6 mA 5.3 mA

6 22.5 mA 6.8 mA 5.3 mA 7 23.8 mA 6.9 mA 5.3 mA 8 25.0 mA 7.0 mA 5.3 mA

Table 4.1 Current consumption at 12 VDC depending on the scan rate

(5 MHz version)

Hardware Manual COMBILOG 1020

The above values in table 4.1 are based on an internal clock frequency of 5 MHz (low power version) and an ambient temperature 20°C and are only valid if LEDs and LCD-display are switched off. At an internal clock frequency of 20 MHz (standard version) the basic power consumption is about 25 mA, independent of filter frequency and number of configured channels, rising up to 65 mA during measurement (for about 100 ms per channel at 50 Hz filter).

Note: A scan rate of 0.5 s causes an unsignificant higher variation of instantaneous values but does not affect the averaging.

4.6 Signal Processing

Arithmetical averaging is carried out using several measuring values. The averaging interval, which is the same for all channels, can be set to one of the values 1, 2, 3, 4, 5, 10, 15, 20, 30 seconds or 1, 2, 3, 4, 5, 10, 15, 20, 30 minutes or 1, 2, 3, 4, 6, 8, 12 hours respectively. The calculated values are finally stored in the memory. With the configuration software the kind of averaging is selectable: Normal averaging or averaging of wind direction (consideres the discontinuity at NORTH). For counter variables not the average, but the number of pulses is calculated. A change of the average interval can be intitiated by certain program conditions, thus featuring temporary higher time resolution of measured signals.

Hardware Manual COMBILOG 1020

5 FUNCTIONAL DESCRIPTION

The datalogger COMBILOG 1020 has a total of 32 logical channels for the collection, processing and output of various kinds of sensor information. These 32 channels can be configured as:

 Analog Input Channel  Digital Input Channel  Digital Output Channel  Arithmetic Channel  Setpoint Channel  Alarm Channel

For each channel various kinds of channel information and processing functions can be determined. The table in appendix C gives a survey of the channel set-ups with the datalogger COMBILOG 1020. The channel set-ups are carried out by means of the configuration software.

Hardware Manual COMBILOG 1020

5.1 Analog Input Channel

The Analog Input Channel collects and processes the signals of the most common types of sensors. A large number of standardised sensors is already stored in the COMBILOG’s internal sensor data base. Further sensors can be added by the user.

Following measuring principles are provided:

 Voltage measurement  Current measurement  Resistance measurement  Temperature measurement with thermocouples

For

each of these principles the datalogger COMBILOG 1020 of-

fers several types of measurement. For voltage measurement the types of measurement single-ended and differential can be used. Currents up to 25 mA are directly measured by the datalogger. Current measurements of more than 25 mA can be carried out by measuring voltage drop at an external shunt. Resistance measurings can be carried out in 2-, 3- and 4-wire technique.

Hardware Manual COMBILOG 1020

Voltage Measurement

Two methods are available for voltage mesurement: single-ended and differential measurement.

With the single-ended type the voltage to be measured is connected between an analog input (In+) and analog ground (AGND). Differential measurements are realized by using two analog inputs (In+ and In-). Measuring range is between 0 and ±10 V.

Note: With differential measurements both voltages have to be within 10 V referred to AGND (Common-Mode-Range).

It is recommended to connect the In- to A

GND

with a high ohmic

resistance.

Hardware Manual COMBILOG 1020

Voltage Measurement

In +

AGND

U = U1

A I N 2A I N 1

measuring voltage U

connection scheme circuit

Figure 5.1 Voltage measurement - single-ended

Connection scheme Circuit

AIN 1 AIN 2

In-

AGND

In+

measuring voltage U U = U1 – U2

Figure 5.2 Voltage measurement - differential

Connection scheme Circuit

Hardware Manual COMBILOG 1020

Current Measurement

For current measurement the current source is connected between

an analog input (In+) and analog ground (A

GND

). The load

required for measurement is controlled by an internal resistor R

int

to 100 Ω. The power capacity of this shunt is limited to 125 mW. This results in a measuring range of 25 mA maximum.

Higher currents can be measured by means of an external resistor which is connected parallel to the current source to the analog signal input and analog ground (A

GND

). The power capacity of this external shunt has to be adapted to the current source to be measured, so that the voltage occurring at the analog input does not exceed +10 V. The analog input is configured as voltage input. The voltage has to be divided by R

ext

Note: The precision of the current measurement with external shunt depends on the precision of the resistor being used.

Note: The input resistance of the current measurement channel depends on the current to measure!

Hardware Manual COMBILOG 1020

Current Measurement

measuring current I

In +

I = U1 / Rint

Rint

AGND

A I N 2A I N 1

connection scheme circuit

Figure 5.3 Current measurement with internal shunt

measuring current I

external shunt

In +

I = U1 / Rext

Rext

AGND

Rext

A I N 2A I N 1

connection scheme circuit

Figure 5.4 Current measurement with external shunt

Connection scheme

Circuit

Hardware Manual COMBILOG 1020

Resistance Measurement

Resistance measurement is carried out by means of voltage measurement at a resistor, measuring the resulting voltage drop. The constant current required for the resistance measurings is provided by the internal supply of the datalogger.

For this purpose the sensor module connects a supply point internally with the analog measurement input via a reference resistor R

. The voltage drop Uo via resistor Ro is required as a reference for further signal processing by the module. The resistance value of the sensor can be calculated from the input signals U

a multiple of the reference resistor R

. Measuring range is be-

tween 0 and 20 kΩ.

Note: The datalogger COMBILOG 1020 supports resistance measurement in 2-, 3- and 4-wire technique. With resistance measurement in 2-wire technique the supply lines cause an additional voltage drop, thus distorting the measuring result and influencing the measuring accuracy. Therefore it is necessary to pay attention especially with resistance measurement in 2-wiretechnique. Wires with impedance as low as possible should be used. Make sure that the leads are well connected to the datalogger and the sensor. With resistance measurement using 3wire technique the potential on the supply lines will be subtracted by software. Therefore 2 measurements are necessary, resulting in double measuring time. With resistance measurement in 4-wire technique the drop of potential is picked up directly at the sensor, so that the measuring results are not influenced by the supply lines.

Hardware Manual COMBILOG 1020

Resistance Measurement

measuring resistance

In +

AGND

∆Rx = U1/U0 * R0, Rx = 2*RL

A I N 2A I N 1

connection scheme

circuit

Figure 5.5 Resistance measurement in 2-wire technique

Connection scheme Circuit

AIN 1 AIN 2

measuring resistance Rx = (U1/U0-2*U2/U0) * R0, ∆Rx=0

Figure 5.6 Resistance measurement in 3-wire technique

measuring resistance

Source

AGND

In +

In -

U2-U3

∆

Rx = (U2-U3)/U0 * R0, Rx = 0

A I N 2A I N 1

connection scheme circuit

Figure 5.7 Resistance measurement in 4-wire technique

SOURCE

Connection scheme

Circuit

Connection scheme

Circuit

Rx = (U2-U3)/U0 * R0, ∆Rx = 0

Rx = U1/U0 * R0, ∆Rx = 2*RL

Hardware Manual COMBILOG 1020

Temperature Measurement with Thermocouple

Thermocouples consist of two “thermoelectric wires” made of different materials (e.g. platinum and platinum rhodium) that are welded to eachother at one end. If the contact and the other ends of the thermoelectric wires have different temperatures, a “thermoelectric voltage” U

appears at the contact of both thermoelectric wires. This voltage is largely proportional to the temperature difference. It can be measured and used for temperature measurement purposes. With datalogger COMBILOG 1020 the thermoelectric voltage is measured differentially.

Since thermocouples can only measure a temperature difference (difference between temperature to be measured and temperature at the connecting terminals on the sensor module), a terminal temperature (internal cold junction compensation, TC

int

) or a known temperature reference (external cold junction compensation, TC

ext

) also have to be determined.

With measurement of temperature with internal cold junction compensation an additional temperature sensor is necessary to measure the temperature ϑ

at the “cold” terminal. A special cold junction terminal is available, where a Pt100 temperature sensor is integrated directly in the terminal block. The temperature of the test point is determined on basis of linearisation trace to ϑ

Lin(U

+Lin

-1

ϑk).

Hardware Manual COMBILOG 1020

If the temperature is measured by external cold junction compensation, a second thermocouple of the same type is required, which is connected in series with the first one. The polarity is selected so that the thermoelectric voltages subtract each other. The second thermocouple is set to a fixed reference temperature

(mostly ϑr = 0°C). The datalogger then calculates the tempera-

ture at the measuring position by means of the linearization curve as ϑ

= Lin(Ux+Lin-1 ϑr). The datalogger will be informed about the

reference temperature ϑ

via the configuration software (“cold

junction temperature”).

Hardware Manual COMBILOG 1020

Temperature Measurement with Thermocouple

Connection scheme Circuit

ϑ = Lin ( U1+ Lin

-1

ϑk)

ϑ = Lin‘ ( U2)

Picture 5.8 Temperature measurement with internal cold junction

compensation by special terminal clamp ICJ 104

Connection scheme Circuit

AGND

Ω

AIN 1 AIN 2

Ω

In-

SOURCE

In+

ϑ = Lin ( U1 + Lin

-1

ϑp)

Picture 5.9 Temperature measurement with external cold

junction compensation

AGND

In-

SOURCE

In+

Ω

ICJ 104

SOURCE

AGND

In-

In+

AIN 1

AGND

In-

In+

AIN 2

Hardware Manual COMBILOG 1020

5.2 Digital Input Channel

The following functions can be realized by means of the Digital Input Channel:

 Digital status recording  Frequency measurement  Counter  8-bit-graycode-transducers, Type 4122  8-bit-status input, with additional (external) module

The above mentioned functions are based on incremental measurings except the digital status and graycode recording. Incremental measuring means to count while measuring. Pulses are counted e.g. from wind speed sensors.

Furthermore it is possible to connect up to 6 sensors with a serial 8-bit-graycode-output to the COMBILOG 1020, e.g. wind direction sensor type 4122.

By means of an external module type 1025 8 bit status signals can be measured at each input. This module converts the 8 bit into a serial signal, and the COMBILOG will compose it to 1 byte again.

Hardware Manual COMBILOG 1020

Digital Status Recording

For the acquisition of digital status information (on/off, closed/open, left/right, etc.) the signal fed to the digital input is collected and is held ready for further processing in the datalogger COMBILOG 1020 or for transmission via bus.

The digital input is set (switch closed) as long as the signal voltage remains under the threshold value of 1.0 V. The digital information can be scanned as 1/0 information via bus.

Hardware Manual COMBILOG 1020

Digital Status Recording

Anschlußschema

I/O 1

0 V

Schaltung

+10 .. 18 VDC

0 V

TH. FRIEDRICHS & CO.

D I G I T A L

I/O 1

Figure 5.10 Digital status recording

I/O 1

status

"0" "1" "0" "1"

signal diagram:

connection scheme

Circuit

Connection scheme

Signal diagram:

Hardware Manual COMBILOG 1020

Frequency Measurement

With frequency measurements the datalogger counts the pulses within a certain time interval at the digital input. The user can preset this time interval by setting the time base (TB) in the range between 0.1 sec and 10 sec. The frequency is calculated by the sensor module from the number of pulses and the time base TB as:

frequency f =

number of impulses per time interval TB

length of time intervall TB

With frequency measurements always the negative signal edge (1

-> 0) is counted.

The lower the frequency

f, the larger the interval between two

pulses, and the larger the time base

TB has to be. On the other

hand the updating of the measured value decreases with an increasing time base. Thus the time base should be selected so as to make

TB ≈ 1/f

, fu being the lowest frequency respectively the smallest change in frequency to be determined by the datalogger. The error with frequency measurements thus amounts to

∆

f = fu =

1/TB

Note: The high-end frequency for the frequency measurement,

i.e. the highest frequency to be measured, depends on the internal clock frequency of the processor. It is 1100 Hz for the 5 MHz version (low power version) and 2000 Hz for the 20 MHz version (standard version).

Hardware Manual COMBILOG 1020

Frequency Measurement

Anschlußschema

I/O 1

0 V

Schaltung

+10 .. 18 VDC

0 V

TH. FRIEDRICHS & CO.

D I G I T A L

I/O 1

Figure 5.11 Frequency measurement

I/O 1

time base

TB TB TB

counting

1231231231

measurand

(TB = 5 sec)

signal diagram:

- high level:

TB TB TB

12112

- low level:

0,6 Hz 0,6 Hz 0,6 Hz

0,4 Hz 0,2 Hz 0,4 Hz

pulse

I/O 1

time base

counting

measurand

(TB = 5 sec)

pulse

connection scheme circuit

Connection scheme

Circuit

Signal diagram:

Hardware Manual COMBILOG 1020

Progressive Counter

When configuring a digital input as a progressive counter the datalogger

COMBILOG 1020 constantly monitors the digital input

for a signal variation. If a negative signal edge (1

-> 0) occurs at

the input, the current result is increased by 1.

The values may range from -2

to +(2

-1) (about -2.1 to +2.1 bil-

lion). Above +2

-1 the counting continues with -231. The values can be reset to zero via the bus interface or internally after the procedure of the averaging interval.

Note: The maximum counting rate depends on the internal clock

frequency of the processor. It is 1100 Hz for the 5 MHz version (low power version) and 2000 Hz for the 20 MHz version (standard version).

Note: After a voltage cut-off the counter is reset to zero.

Hardware Manual COMBILOG 1020

Progressive Counter

Anschlußschema

I/O 1

0 V

Schaltung

+10 .. 18 VDC

0 V

TH. FRIEDRICHS & CO.

D I G I T A L

I/O 1

Figure 5.12 Progressive Counter

+1 +1 +1 +1 +1

n+1 n+2 n+3 n+4 n+5

signal diagram:

I/O 1

counting

measurand

pulse

connection scheme circuit

Connection scheme Circuit

Signal diagram:

Hardware Manual COMBILOG 1020

5.3 Digital Output Channel

The Digital Output Channel supports:

 digital status output, host-controlled  digital status output, process-controlled

Via the digital inputs/outputs I/O 1 to I/O 6 on the datalogger

COMBILOG 1020 digital status can be output in digital form, ac-

cording to the configuration. A typical case of application would be e.g. the local output of an acoustic or optical signal in case a limiting value is exceeded or undershot by a measured value. All outputs are open-collector.

The supply voltage can range from 10 up to 18 VDC. It has to be either supplied externally or taken from the power supply of the datalogger.

The status of the digital output can be scanned as 1/0 information via bus.

With the host-controlled digital status output, the digital output is set according to the status information received by the datalogger via bus.

With the process-controlled output of status information the datalogger monitors measured values, resp. sensor channels from excess of default threshold values. The digital output is set if one or several threshold conditions are fulfilled.

Hardware Manual COMBILOG 1020

The thresholds can be freely defined by the user. The user can also preset the logical signal level (see also the configuration software

COMBILOG.EXE).

Thus it is possible to activate a digital output depending on a specified time or periodically. This can be realized in connection with an arithmetic channel, that can calculate the time or a time interval from the internal real time clock. A typical application is to switch off a modem after a specified time to reduce the power comsumption of battery powered systems.

Hardware Manual COMBILOG 1020

Digital Status Output:

SUPPLY RS 485 RS 232

0.1 AM

U+

I/O 1

U+

connection scheme circuit

Figure 5.13 Digital status output

I/O 1

status

"0" "1" "0" "1"

signal diagram:

Connection scheme

Circuit

Signal diagram:

Hardware Manual COMBILOG 1020

5.4 Arithmetic Channel

By means of the Arithmetic Channel sensor channels and constants can be connected with eachother via arithmetic operations. The result is allocated to the Arithmetic Channel. The formula can contain up to 20 operands. The calculation is performed with a stack depth of 20. The value is handled as a 4-byte floating point format with 24 significant bits according to IEEE, standard 754. The full scale is –10

to +1037.

A typical application for the Arithmetic Channel is e.g. the determination of a value that cannot be measured directly, but calculated from other values (e.g. power as a product of voltage and current). Or the Arithmetic Channel is used for further mathematical preparation of a measuring signal, in order to obtain a particular desired format, linearization or similar.

Special functions for which the existing commands are not sufficient, can be carried out by a user specific download program for the COMBILOG 1020. For this case, some implemented special functions can be used for assistance.

Note: The calculation time of an Arithmetic Channel is 0.6 ms.

The overall calculation time is the sum of the times of all operands in the formular plus 0.6 ms.

Hardware Manual COMBILOG 1020

Arithmetik Operators

Operationen Kurzzeichen Zeit

Addition + 0.80 ms Subtraction - 0.80 ms Multiplication * 0.80 ms Division / 1.10 ms Modulo % 0.90 ms Truncate value trunc 0.20 ms Minimum value min 0.20 ms Maximaler value max 0.20 ms Absoluter value abs 0.10 ms Square root sqrt 2.68 ms Exponential function to base e exp 3.92 ms Logarithmto to base e In 3.70 ms Logarithmi to base 10 log 3.80 ms Sine sin 3.20 ms Cosine cos 3.60 ms Tangent tan 3.60 ms Inverse sine arcsin 3.20 ms Inverse cosine arccos 7.00 ms Inverse tangent arctan 3.20 ms Lowest value from a selection Low 1.50 ms Highest value from a selection high 1.50 ms XY power 8.80 ms Integrator integ 0.20 ms Differentiator deriv 0.20 ms Read from external module read

Write to external module write

Time /seconds of the day) SecondsOfDay 1.10 ms Sample rate SampleTime 0.10 ms Free space on PCMCIA-Card PCMCIASpace 0.90 ms Free space in RAM RAMSpace 1.70 ms Application specific function 1 spec 1

Application specific function 2 spec 2

Application specific function 3 spec 3

Application specific function 4 spec 4

Dewpoint from temp. and humidity DP1 Dewpoint from dry and wet temp. DP2 Humidity from dry and wet temp. RH Standard deviation Sdev vector of wind speed WSv vector of wind direction WDv

1)No specification available as the time depends to the specific function and the program.

Table 5.1 Arithmetic operators and processing times

Hardware Manual COMBILOG 1020

The times given in the above table are based on an operating frequency of 20 MHz. The 5 MHz version requires time values 4 times higher.

Remarks:

 Division (/)

When dividing by zero, the positive full scale (+10

) will be assigned to the Arithmetic Channel if the numerator is positive and the negative full scale (-10

) will be assigned if the nu-

merator is negative.

 Square root (sqrt)

The square root of a negative number is zero.

 Logarith to Base e (In)

For avalue

≤ 0 the negative full scale will be assigned to the

Arithmetic Channel.

 Logarithm to Base10 (log)

For a value

≤ 0 the negative full scale will be assigned to the

Arithmetic Channel.

 Arc functions (sin, cos, tan)

The arc values must be taken in radians (2

π = 360°). If calcu-

lating the tangens, the positve full scale will be assigned to

the Arithmetic Channel for the arc value

and the negative

full scale for the arc value -

 Inverse functions for sin (arcsin), cos (arccos), tan (arctan)

The results of the inverse functions are given in radians

π = 360°). At the function arcsin the value +

will be as-

signed to the Arithmetic Channel for a value

>1 and the value

–

will be assigned for a value <-1. At the function arccos

the value 0 will be assigned to the Arithmetic Channel for a value

>1 and the value will be assigned for a value <-1.

Hardware Manual COMBILOG 1020

 Minimum and maximum of a channel value (min, max)

With this function the minimum and maximum value of a channel appeared since the last reset has been triggered off can be determined (“

pull-pointer-function”). The result value

can be reset to the actual value of the measured channel via the bus or at the end of the average interval.

 The functions read and write enable the datalogger to receive

measured values from other modules connected to the same bus, resp. to send values to them (master function)

Note:

Logic combinations, e.g. if-then relations, are not yet possible respectively would require a user-specific software (upon request).

Hardware Manual COMBILOG 1020

5.5 Setpoint Channel

This channel features transmission of values via bus to the datalogger

COMBILOG 1020. The values are allocated to the set-

point-channel and are thus at the disposal of the datalogger for further processing.

A typical application for the setpoint-channel is e.g. the dynamic variation of control thresholds.

5.6 Alarm Channel

The Alarm Channel has the same features as the processcontrolled digital output channel, the only difference is that the status information is not output locally at the digital output, but can only be scanned via the bus.

5.7 Threshold Values

The user can preset the conditions for process-controlled digital status output on the datalogger and for the output of an alarm signal via bus. This is carried out by means of the configuration software

COMBILOG.EXE.

Hardware Manual COMBILOG 1020

5.8 Error Handling

The datalogger

COMBILOG 1020 can detect independently cer-

tain defects, which are result of a line break, short-circuit or communication interrupt, for example. For these defects the user can preset a certain behaviour for the datalogger via the configuration software.

In case of a sensor failure the last valid value can be maintained, set to the corresponding limits or set to a default value.

Furthermore the COMBILOG 1020 can send messages via modem or SMS automatically to report errors or other conditions, e.g. if the data memory capacity becomes zero.

Hardware Manual COMBILOG 1020

6 DISPLAY / MENU OPERATION

6.1 Display and Operation

The datalogger

COMBILOG 1020 has a display with 2 lines of 16

characters each, in order to allow the indication of the measured values of each channel. Furthermore the settings of the datalogger can be recalled and changed if desired (therefore the input by the press/ rotary knob must be unlocked; refer to the corresponding section 6.2 “Menu Items“) The operation is performed via the combined press/rotary knob at the right side of the display. By turning the knob the menue items or informations can sequentially be indicated. A confirmation or a call of a function is performed by pressing the knob.

6.2 Menu Items

In the following diagrams all display pictures with the corresponding operation steps are indicated. Following symbols are used for the operation steps:

Symbols:

...... turn the knob clockwise

...... turn the knob counter clockwise

...... press the knob briefly (confirmation)

...... press the knob for approx. 1 second minimum

.............. (abortion)

Hardware Manual COMBILOG 1020

Main Menu:

Th. Friedrichs Data - Logger

Meas. of Voltage

0.831 V

Current (Ch. 2)

22.5 mA

Temperature 35 °C

PCMCIA: 488kB free: 385kB

Date : 16.02.95 Time : 16:08:58

Channel 1

Channel 2

Channel n

(1)

Note: The number, designation and indication of the measured

value of the channels depend on the configuration.

Combilog 1020+

U3.00

LOG: 208 2048KB free: 209d

Hardware Manual COMBILOG 1020

Configuration Menu

COMBILOG 1020+ U 3.00

Define Display Contrast ?

Scan Rate : 10s Averaging : 60s

Auto Off : OFF LEDs : ON

"Location" Addr.: 1 19200E

Knob Input locked

Main Menü

Note: If the push/turn selection knob is pressed at any point in

the configuration menu for about 1 second you will return to the initial position in the main menu.

Hardware Manual COMBILOG 1020

Setting of the Display Contrast:

Display Contrast 88

Define Display Contrast ?

Configuration Menu

Display Contrast 92

Display Contrast 84

Note: The value of the display contrast can be set in steps from 0

to 100. With low values the display will be set dark and with the value 100 it will be set to maximum brightness.

Hardware Manual COMBILOG 1020

Setting the Scan Rate and the Averaging Interval:

Configuration Menu

Scan Rate: 10s Averaging: 60s

Scan Rate: <10s> Averaging: 60s

Change

Scan Rate: 1s Averaging: < 60s >

Note: The scan rate determines after which time interval the

measured values of the channels will be measured again. Scan rate is selectable between 0.5s and 1h. At “Averaging“ the averaging interval can be set. It determines the time interval for the averaging of the measured values. Averaging interval is selectable between 1s and 12h. In the example the measured values will be measured again every 10 seconds and after 60 seconds the average value will be calculated (here by means of 6 measured values).

Hardware Manual COMBILOG 1020

Setting of the Automatic Switch Off and the LED Display:

Auto OFF : OFF LEDs : ON

Configuration Menu

Change

Auto OFF :<OFF> LEDs : ON

Auto OFF : ON LEDs :< ON>

ON <-> OFF

Note: With the automatic switch off function the datalogger can

be set to the saving mode if no operation is made by the press/ rotary knob in a certain time interval (30 seconds). In this case the display will be set off until a further operation takes place. If “LEDs“ is set to

ON the LED-display is switched on and the two

LEDs RUN and ERR on the front of the datalogger show the actual operating state (mode) of the datalogger. With the selection

OFF the LEDs will be switched off.

Hardware Manual COMBILOG 1020

Setting of the Baud Rate and the Address:

Configuration Menu

"Location" Addr.: 1 19200N

BaudRate: <19200N> Address: 1

Change

BaudRate: <9600N> Address: 1

Change

Note: Possible values for the baud rate are 2400, 4800, 9600,

19200 and 38400 bps. Additionally to the baud rate the parity can be set . Possible values are N (no parity), E (even parity) and O (odd parity). For the address a value between 1 and 126 can be set.

Hardware Manual COMBILOG 1020

Lock or Unlock the Press/Rotary Knob Input:

Configuration Menu

Knob Input <enabled>

Knob Input <disabled>

Knob Input locked

Normally the changing of configuration parameters by the press/rotary knob is locked (disabled). To change the parameter the press/rotary knob must be unlocked (enabled).

Note: If no operation is performed at the datalogger for approx.

30 seconds it will return to the main menu and the press/rotary knob input will automatically be locked.

Hardware Manual COMBILOG 1020

Channels settings:

Meas. of Voltage

0.831 V

Main Menu

Offset

0.00000

Factor

1.00000

Default Value 55

New Set-Value

55.00000

(1)

(2)

In order to change the values the press/rotary knob must be pressed. Thereby a cursor will be set on the first character of the value. Pressing the knob again moves the cursor one character to the right. The value at the place of the cursor can be altered by turning the knob. Clockwise (=upwards) or counterclockwise (=downwards).

Note: Depending on the type of channel different settings can be

made.

(1)

the definition of offset and factor is possible for the analog

input channel, the digital input channel and the digital output channel. These settings are used to convert the measurement value from the unit of the measured value to the unit of the measurement display.

(2)

For the setpoint channel a setpoint value can be defined if

this is allowed by the configuration software

COMBILOG.EXE. This value can be used by the datalogger

for further processing (e.g. for the arithmetic channel). For the arithmetic channel and the alarm channel no settings can be made.

Hardware Manual COMBILOG 1020

Delete the Data Memory:

Main Menu

Delete Data Memory?

RAM: 0 248kB available: 36h

data memory will not be deleted

data memory will be deleted

The display shows the number of stored datasets and the maximum capacity of the data memory in the first line. The second line shows the approximate time until the data memory is filled. This time is displayed in days (d) or hours (h) and is calculated by the datalogger assumed that the average interval is constant.

Note: The data memory of the internal RAM can only be deleted

if no PCMCIA memory card is inserted in the datalogger. By deleting the memory all stored events (measured values of the channels) will be lost.

Note: In case of using an SRAM memory card the internal data

memory is not used. The card must not be pulled out, because all data will be lost after reinserting!

Hardware Manual COMBILOG 1020

Setting of the Date and Time:

Date : 16.02.95 Time : 16:08:58

Main Menu

Set Date?

Set Time?

Date TT:MM:JJ

16.02.95

Time HH:MM:SS 16:08:58

(1)

(2)

In order to change the date and the time the press/rotary knob must be pressed when the time

(1)

respectively date

(2)

.is displayed. For this purpose a cursor will be set on the first character of the date respectively time indication. Pressing the knob again will move the cursor one character to the right. The value at the place of the cursor can be altered by turning the knob.

Note: The time will be stopped if the press/rotary knob is pressed

in the main menu, date and time display. The time will continue running if the date or time setting is confirmed by pressing the knob.

Hardware Manual COMBILOG 1020

7 DATA STORAGE

7.1 General Remarks to Data Storage

Data storage with the COMBILOG 1020 can be accomplished in three different manners:

Internal RAM: 252 KByte are available as circulated buffer for

data recording.

External PCMCIA SRAM Card: This is an extension up to 32

Mbytes memory. The internal RAM will be deactivated if an SRAM Card is used, i.e. the card replaces the internal RAM. The maximum number of datarecords is limited to 65565.

External PCMCIA Flash Card: The records are continuously

stored on this card. The maximum memory capacity is 16 MByte.

7.2 Modes of Data Storage

No Data Storage

In this mode the COMBILOG 1020 operates as measuring module, processes measuring values and sends the results to a PC upon command.

Continuous Data Storage

This is the normal operation of the datalogger. The measured values, selected for storage, are continuously written to internal or external memory, with the preset averaging interval.

Hardware Manual COMBILOG 1020

Conditional Data Storage

Measured values are stored in the memory as long as a condition defined by the

Configuration Program is valid (e.g. a threshold is

exceeded).

Conditional Data Storage with Zoom Function

In this mode two time bases for data recording are available. The selection between these time bases depends on a condition selected by the

Configuration Program.

7.3 Internal Data Storage

The COMBILOG 1020 is delivered with 256 Kbytes RAM memory. For data recording 252 Kbytes memory are available as circulate memory (first in, first out). If the memory is read out, at first the oldest record will be output and the corresponding space is enabled. The data memory can be read out via one of the serial interfaces. Communication commands are described in chapter 11.8. Every record consists of a length information, date, time and measured values.

L Time M1 M2 ... Mx S1 S2 … Sx

L Length of record (2 Byte) Time Date and time of record (8 Byte) M1 First measured value (4 Byte) M2 Second measured value (4 Byte) Mx Last measured value (4 Byte) S1 First external channel (only with master function) S2 Second external channel Sx Last external channel

Hardware Manual COMBILOG 1020

Memory demand for one record:

Number of bytes = 10 + 4* number of measured values

The duration of data recording until the data memory is filled can be calculated by the following formula:

864*)*410(

*2580nM

d = duration of data recording in days

n = number of values to be stored (without date and time)

M = averaging interval in seconds

Example:

Storage of eight measured values per hour.

Number of Bytes = 10 + (4 * 8) = 42 bytes per record Memory demand per day = 24 * 42 = 1008 bytes

At 256 Kbytes internal RAM 2580 * 3600/ (42 * 864) = 255,9 days can be recorded.

The data memory is buffered by a capacitor (gold cap), that ensures preservation of data for several days in case the main power is switched off.

Hardware Manual COMBILOG 1020

7.4 External Data Storage with PCMCIA SRAM Card

A linear PCMCIA SRAM Card can be plugged into the PCMCIA slot to replace the internal data memory. Depending on the type of card up to 32 Mbytes are available for data storage. The structure for data storage is the same as for the internal RAM.

Note: After plug-in a PCMCIA SRAM Card the card and the data

in the internal RAM will be erased automatically. If the card is plugged out the data get lost! Data can be read out via one of the communication lines only!

Note: Independing from the capacity of the used SRAM memory

card datarecording is limited to 65536 datasets!

7.5 External Data Storage with PCMCIA Flash Card

The COMBILOG 1020 can be equipped with PCMCIA Flash Cards of the Intel Series 2 with 2 MB or 10 MB. On the flash card the data will be stored in a file named COMBILOG.LOG, containing also additional information about channel configuration. This file occupies the hole memory space of the card, independent of the real written number of data. If the memory card is filled, no further data will be recorded. Data recording is performed in ASCII format. A separation mark (";" or tabulator) and the decimal character ("." or ",") is selectable by the user.

If a PCMCIA Flash Card is plugged in a COMBILOG 1020 during operation all data from the internal RAM will be transmitted to the PCMCIA Flash Card when the next record is to be stored. During this time continuous data storage is interrupted. The following records are stored on the PCMCIA Flash Card. If no more memory is available on the card the records are stored on the internal RAM again (circulate buffer).

Hardware Manual COMBILOG 1020

Note: The datalogger can write data to pre-formatted memory

cards only. The following file systems are supported:

- Microsoft Flash File System

- TrueFFS

-FTL (MSystems) To read the cards on a PC a driver for the respective file system must be installed. At present only 16 bit drivers are available for the file systems above, so it can not be used for Windows NT/2000. Theodor Friedrichs & Co. delivers pre-formatted flash memory cards, that can directly used for the Combilog.

Structure of the data file COMBILOG.LOG:

Identification COM1020

M2.10U3.00 Location COMBILOG Serial No 123456 Sample Rate 1 Store Rate 3600 Code Time Variable

Variable 2 ... Variable

n 0 01.11.99 08:00:00 3.45 1.28 ... 3.44 0 01.11.99 08:00:00 3.45 1.28 ... 3.44 0 01.11.99 08:00:00 3.45 1.28 ... 3.44 0 01.11.99 08:00:00 3.45 1.28 ... 3.44

Structure of a record:

K T Time T M1 T M2 T … T Mx T S1 T S2 T … Sx CR LF

K Sign “0” for data record T Separation mark (Tabulator or “;“) Time Date and time of the data record

(DD.MM.YY HH:MM:SS) M1 First measured value M2 Second measured value Mx Last measured value S1 First external channel

Hardware Manual COMBILOG 1020

S2 Second external channel Sx Last external channel CR Carriage Return LF Line Feed

Note: With the Configuration program a”;” or a “TAB” (ASCII

hex

) can be selected as delimiter and a “:” or a “;” is selectable

as decimal point.

Memory demand for one record:

NumBytes = 21 + field length (M1) + 1 + field length (M2) + 1…… + field length (Sx) +1 NumBytes = 21 + number of measured values * (8 +1) (fixed field length of 8 characters)

Example:

Storage of eight measured values per hour: NumBytes = 21 + 8 *(8 + 1) = 93 bytes per record Memory demand per day = 24 * 93 = 2232 bytes

2 Mbytes Flash Card: 1904000 / 2232 = 853 days

Following equation can be used:

86400**l

d =

d = period of data recording in days

k = capacity of the memory card in byte

l = length of one data set in byte

M = average interval in seconds

Hardware Manual COMBILOG 1020

8 MASTER FUNCTION

8.1 Master function

The two interfaces and the master function of the COMBILOG 1020 allows a configuration of a complex measurement system. In such a system with activated master function the datalogger as master is able to read out the other bus users (slaves)

This feature is used to extend the number of inputs and outputs of the COMBILOG 1020 in case the 8 analog inputs and 6 digital inputs/outputs of the datalogger are not sufficient. Other COMBILOG’s 1020 can be connected to the RS-485 interface as slaves. The master datalogger reads out the measured values (actual instantaneous values only!) of the slave modules automatically via the bus and stores them in its memory . By this method complex systems to record up to 92 channels can be realised easily.

The advantage of this master function is a flexible distribution of a number of inputs and outputs and the sensors can be located in an area over some kilometres. The data storage is central in the master datalogger either in the internal buffered RAM or on a PCMCIA card.

These data can be read out directly via the RS232 interface or via telephone or GSM modem.

Arrangement of such a measurement system with COMBILOG 1020 and slave moduls is described by following steps:

Hardware Manual COMBILOG 1020

 Configure all slave modules with the same bus parameters as

the master datalogger (same protocol type, same baudrate and parity). All modules must have different modules addresses.

 Connect the master datalogger via RS232 with the host PC

and start the configuration program.

 Set the bus parameter for the master function with module

settings.

Baudrate is selectable between 2400 and 38400 bps

and independent of the settings of the RS232 interface.

 Select all values to be measured by the master datalogger by

defining the module address and the channel number of the corresponding slave module. Up to 60 external channels can be selected.

 Connect all slave modules with the master via the RS485 bus.

After downloading the configuration to the master datalogger the data transmission between master and slave modules is started.

Note, that the configuration of slave modules is not possible after activating the master function. All collected slave values will be added to the normal dataset, that is defined by the logging function of the master. No further calculation (averaging etc.) is executed. If averaging is necessary, use the

read function of the arithmetic channel!

The scan rate corresponds to the “Logging Interval”

Within one RS485 bus system, only one COMBILOG 1020 can be defined as master.

Hardware Manual COMBILOG 1020

Bild 8.1 Example Master Slave System

Hardware Manual COMBILOG 1020

9 INITIATION AND TEST

9.1 Before Connecting the Device

Before connecting the supply voltage to the datalogger

COMBILOG 1020, once again check all connections. Watch that

the supply voltage never exceeds 18 VDC.

9.2 After Connecting the Device

After connecting the supply voltage the datalogger displays the current operating state on the two LEDs at the front of the device (if the LED-display has not been switched off). The meanings of the LEDs are given in table 9.1 on the following page. If the module was switched off for a longer time, the settings of date and time should be checked and corrected if necessary (see chapter 6.2).

9.3 Configuration of the Datalogger

Before entering into operation the datalogger has to be programmed and configured as to its specific application. In most cases the programming has already been carried out on delivery (see status of RUN-LED and ERR-LED, table 9.1). The configuration has to be carried out by the user by means of the configuration software

COMBILOG.EXE on a PC. The installation proce-

dure is described in APPENDIX E.

Hardware Manual COMBILOG 1020

RUN

(green LED)

ERR

(red LED)

meaning

off

The supply voltage has been selected too low or the power supply cannot supply the required power.

off flash

The datalogger is in the monitor mode. A valid program has not yet been loaded; the appliance is not yet ready for operation.

There is a sensor error detected. Possible causes may be: 1. wrong configuration, 2. line break or short circuit, 3. measured value too high or too low.

flash flash

The datalogger is in the download mode. Currently a program or a configuration is transmitted to the datalogger.

off

The supply voltage has been connected correctly. There is no error. Data transmission to the module via bus is not active.

There is a sensor error detected. Possible causes may be: 1. wrong configuration, 2. line break or short circuit, 3. measured value too high or too low.

short off X

A telegram has just been dispatched from the datalogger via the bus to a control system or to a PC.

Table 9.1 Assignment of LED functions (flash frequency approx. 1Hz)

Hardware Manual COMBILOG 1020

10 STRUCTURE OF THE BUS TOPOLOGY

The coupling of the datalogger

COMBILOG 1020 to a communi-

cation bus is performed via an integrated RS485 interface. The second interface, the RS232 computer interface, is only useable in order to build point-to-point connections for a distance of max. 20 m (65 feet). At the

COMBILOG 1020 the same data will per-

manently be given out. Only the physical characteristics of the two interfaces are different whereas only those of the RS485 are appropriate in order to build a bus topology. The RS485 bus topology is characterized by the following features:

 Bus interface:

RS485, half duplex

 Bus topology:

line pattern, closed at both ends by the characteristic impedance, stub cable to the party max. 30 cm (12 inch).

 Bus medium:

shielded, twisted pair cable

 Transmission speed:

ASCII-protocol: 2400 / 4800 / 9600 / 19200 bps / 38400 bps PROFIBUS-protocol: 9.6 / 19.2 kbps / 38.4 kbps

Hardware Manual COMBILOG 1020

 Line length:

depends on the transmission speed, max. 1.2 km (0.75 miles) per bus segment, max. 4.8 km (3 miles) via a physical bus string with 3 repeaters.

 Number of bus users:

max. 32 bus users per bus segment, max. 127 bus users via a physical bus string.

10.1 Bus Interface

The bus interface in the datalogger is an RS485 interface. Its advantages compared with RS232 connections are a larger number of users, its higher transmission speed, its higher immunity from interferences and the extended line length.

transmission speed

1 K 10 K 100 K

187,5 K

1 M 10 M

[bps]

10 m (32.5 ft)

100 m (325 ft)

1000 m (3.250 ft)

1200 m (3.900 ft)

transmission

600 m (1.950 ft)

RS 232

RS 422 RS 485

route

Figure 10.1 Interrelation between transmission speed and line length

Hardware Manual COMBILOG 1020

10.2 Bus Structure

The bus structure is a line structure where each bus segment will be blanked off with characteristic impedance on both ends. Branches can be build up over a bi-directional signal amplifier, so called repeater. Other than that branches are not permitted (no tree topology). The max. stub to a user is not allowed to exceed 30 cm (12 inches).

The following figures show a few examples for a possible set-up of bus topologies. The meaning of the symbols is:

: bus user,

: repeater and : bus termination.

Figure 10.2 Simple line structure

Figure 10.3 Extended line structure

.....

Hardware Manual COMBILOG 1020

Figure 10.4 Line structure with branches

The RS485 interface permits the simultaneous connection and operation of a maximum of 32 bus users per bus segment. Further bus segments can be constituted via bi-directional repeaters, and thus the number of bus users can be extended to max. 127.

10.3 Transmission Speed and Line Length

The transmission speed with the datalogger

COMBILOG 1020

can be adjusted between 2,400 baud and 38.4 kbps. The permissible line lengths are reduced with increasing transmission speed. At the given transmission speeds these line lengths are about 1,200 m (3,900 feet) per bus segment. With 3 repeaters topologies with a dimension of max. 4.8 km (3 miles) can be set up.

: :: :

...

Hardware Manual COMBILOG 1020

Note: These specifications refer to bus cables with a conductor

cross section of 0.22 mm² and a permissible signal attenuation of max. 6 dB referred to the overall length. According to previous experience the line length can be twice as long if a two-wire circuit with a conductor cross section of at least 0.5 mm² is used.

10.4 Bus Cable

For setting up a bus topology a shielded twisted pair with at least two leads and the following electric characteristic values should be used:

 characteristic impedance : 100 ... 130 Ω at f > 100 kHz  operating capacity : max. 60 pF/m  conductor cross section : min. 0.22 mm² (AWG 24)  attenuation : max. 6dB referred to the overall

length

Hardware Manual COMBILOG 1020

10.5 Bus Plug

For installing the bus cable and the bus interface, 9-channel D-subminiature plugs and sockets are used. The pin assignment for the RS485 connection according to PROFIBUS is given in table 10.2.

plug PIN

RS485-

notation

signal meaning

DB 9

B / B´

C / C´

A / A´

Shield

RxD/TxD-P

CNTR-P

DGND

RxD/TxD-N

CNTR-N

Shield, Protective Ground

Reserved for Power

Receive/Transmit-Data-P

Control-P

Data Ground

Voltage Plus

Reserved for Power

Receive/Transmit-Data-N

Control-N

Table 10.2 Pin assignment D-subminiature plug according to PROFIBUS

Only signal leads A and B (and Shield) are absolutely obligatory for a (shielded) connection. All others can be installed together with these signal leads if required.

Hardware Manual COMBILOG 1020

10.6 Bus Termination

In order to avoid signal reflections on the bus, each bus segment has to be blanked off at its physical beginning and at its end with the characteristic impedance. For this purpose, a terminating resistor Rt is installed between the bus leads A and B. In addition to that the bus lead A is connected via a pull-down resistor Rd to ground (DataGround) and the bus lead B is connected via a pullup resistor Ru to potential (VP). These resistors provide a defined quiescent potential in case there is no data transmission on the bus. This quiescent potential is level

high.

VP (6)

B (3)

A (8)

DGND (5)

bus cable

= 390 2%, at least watt

Ω

= 150 2%, at least wattΩ

= 390 2%, at least wattΩ±±

VP = +5V :

Figure 10.5 Bus termination

Note: The numbers in brackets in figure 10.5 indicate the pin

number for the connection via the 9-channel D-subminiature plug.

Prufibus designation

COMBILOG terminal names

Hardware Manual COMBILOG 1020

The bus termination can be carried out in various ways.

It can either be carried out via external resistors and a separate power supply, independent of the module, according to figure

10.5. In this case we recommend to use the indicated resistors for the bus termination.

Or the bus termination is connected with the bus users at the beginning and at the end of a bus line. Most of the RS485 connections for controls, computers, repeaters, interface converters, etc. offer this option.

Also with datalogger

COMBILOG 1020 this option is given. Via

the bus termination plug which is available as accessory and installed at the right port on the frontside of the device, the bus termination at this module can be additionally connected. Two jumpers which connect the bus with the bus termination in the datalogger are integrated in the bus termination plug.

Note: Instead of the bus termination module separate jumpers

can also be used for the bus termination. In this case, please make absolutely sure that the jumper clips are installed as indicated, and that the bus leads or the bus termination are not shortcircuited by mistake!

Hardware Manual COMBILOG 1020

A B

U+ U-

A B

U+ U-

Steckbrücken

Datenlogger mit

zugeschaltetem

Busabschluß

Datenlogger ohne

zugeschaltetem

Busabschluß

ERR

RUN

TH. FRIEDRICHS & CO.

COMBILOG 1020

D I G I T A L

A I N 8

A I N 7I N 6

Figure 10.6 Bus termination on the COMBILOG 1020

10.7 Shielding

In case of increased interference we recommend to use shielded bus cables. In this case, a shielding should also be carried out for the cables from power supply and for the signal cables.

Datalogger without an additionally connected bus termination

jumpers

Datalogger with an additional connected bus termination

Hardware Manual COMBILOG 1020

There are varying experiences and recommendations concerning the kind of shield connection. In general the shield should be connected with the protector ground (not DataGround!) at each bus connection. If necessary the shield should be earthed additionally several times along the course of the cable. With smaller distances, e.g. with stub cables, the immunity from noise often is improved if the shield is only applied to the stub cable exit.

Bus parties such as controls (PLCs), computers (PCs), repeaters and interface converters, a.s.o., mostly offer the possibility of applying the shield directly to the appliance or to separate shield rails. The shield rails offer the advantage of preventing possible interfering signals from being led to the appliance via the shield. These are already branched off before via the protector ground.

The C

OMBILOG housing has no direct shield terminals. The

shield of the bus cable can be earthed e.g. by so-called shield clamps.

TH. F

D I G I T A L

MEMORY CARD / PCMCIA

SUPPLY RS 485 RS 232

RS-485 Busverbindung

zentraler

Erdungspunkt

Schirmgeflecht

Isolierung

Figure 10.7 Earthing of the bus line shield on the COMBILOG 1020

central

earthing point

braided shield

isolation

RS 485 bus connection

shield clamp

Hardware Manual COMBILOG 1020

Note: The shield must not be connected to bus interfaces A or B!

Note: The shield should always be connected to earth in a large

surface, low-inductive manner.

10.8 PC Bus Connection

The bus interface of the datalogger is based on the RS485 standard. Since most of the hosts are "only" equipped with RS232 interfaces, an interface converter or a plug-in board with RS485 drivers is required for conversion purposes.

Theodor Friedrichs offers a compact interface converter.

Furthermore a repeater module is available from

Theodor Frie-

drichs.

This module can be used as a repeater or as a converter. It also enables to connect the necessary bus termination with a switch. The

repeater/converter has a snap-on mounting for instal-

lation on standard profile rails (DIN rail) 35 mm (1.4 inch) according to DIN EN 50022.

Hardware Manual COMBILOG 1020

100

10.9 Potential Equalization

The difference between the actual physical voltage potentials DGND of all connections with the bus must not exceed ±7 Volt. If this cannot be guaranteed, an equalization has to be provided. For most of the connections this means that the minus connection of the power supply has to be fed-through as a compensating line from connection to connection.

10.10 Adjustment of Address and Baud Rate

Before a control unit (PLC) or a computer (PC) can interchange data with a datalogger via the bus, address and baud rate for the datalogger have to be defined. Following hints have to be considered:

 All devices have to be adjusted to the same baud rate.  Within the bus topology the same address must not appear

twice.

The setting variants for the bus parameters for the datalogger

COMBILOG 1020

are:

bus parameter ASCII-protocol PROFIBUS-protocol

address 1 ..... 127 1 ..... 126

2,400 bps -

baud rate 4,800 bps -

9,600 bps 9,600 bps 19,200 bps 19,200 bps 38,400 bps -

Table 10.3 Setting variants for address and baud rate

for the datalogger COMBILOG 1020

Theodor Friedrichs COMBILOG 1020 Hardware Manual

Specifications and Main Features

Frequently Asked Questions

User Manual