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ELGAS-2 (CP II) communication protocol

Supported device types and versions 
Communication line configuration
Communication station configuration
I/O tag configuration
Changes and modifications
Document revisions

Supported device types and versions

The protocol supports the communication with devices ELCOR-2 and microELCOR-2 (made by company ELGAS) that recalculate a gas quantity.

Communication line configuration

The asynchronous transmission parameter are set according to setting of specific device.

Communication station configuration

  • Communication protocol: Elcor ELGAS-2 (CP II).
  • Station address:

Node address: value in the range of 0 to 65535.

Measure address: value in the range of 0 to 255.

If the address and measure has the 0 value the device must answer obligatorily.

Password for reading: maximum 6 characters is allowed if the password is set in device (only ELCOR-2).

Station protocol parameters

Configuration dialog box  - tab „Parameters".
They influence some optional parameters of protocol. Following station protocol parameters can be set:

Table 1

Full nameMeaningUnitDefault value
Device Type
Selection of device type.ELCOR-2 or microELCOR-2ELCOR-2
Retry Count
Delay between request retry in case of a communication failure.
Wait First Timeout
Delay after sending the request before reading the response.ms100 ms
Wait Timeout
Delay between response readings till its completing.ms100 ms
Max. Wait Retry
Retry count of response reading till its completing.
Static Data Read Period
Static - configuration data read period (only microELCOR-2).min60 min
Hourly Archive Periodic Reading
A period for reading value of hourly archives (0-60 min). Value 0 disables the reading.min0 min
Wake Up Sequence Length
Length 'wake-up' of data which is entered before the call after longer communication pause.0 .. 50 bytes25 bytes
Wake Up Each Query
Insert 'wake-up' data before each query.YES/NONO
Wake Up Character
Form 'wake-up' data sequence from the characters that has this value.0 .. 255255
Group Source Address
Group source address (address of D2000 KOM process).0 .. 655350
Source Address
Source address (address of D2000 KOM process).0 .. 2550
Full DebugHigh level of communication tracking, the loaded values of I/O tags and other debug information are shown.YES/NONO

I/O tag configuration

Possible value types of I/O tags: Di, Ai, Ci, TxtI, TiA.

Device ELCOR-2

Table 2 contains the list of main parameters of device.
Tables 3 to 8 contains the list of variable configuration and informative data according to parameter type. DESC(ind) parameter represents the common data of all parameters. It describes the quantity. The current value of quantity can be acquired by configuration of the I/O tag with numerical address - index ind (number from 1 and more). To find out the technical units - configure text of I/O tag with address UNIT(ind).

Table 2 - Device parameters - Main device parameters

Object descriptionValue typeAddressUnits
Serial number of deviceCi, TxtISN
Referential temperatureAiTB°C
Referential pressureAiPBkPa
Firmware versionTxtIFW
Station nameTxtIDESC
CO2 concentrationAiTAB(0)%
N2 concentrationAiTAB(1)%
Heat of combustionAiTAB(2)MJ/m3
Relative densityAiTAB(3)
H2 concentrationAiTAB(4)%
H2S concentrationAiTAB(5)%
He concentrationAiTAB(6)%
H2O concentrationAiTAB(7)%
O2 concentrationAiTAB(8)%
Ar concentrationAiTAB(9)%
CO concentrationAiTAB(10)%
C1H4 concentrationAiTAB(11)%
C2H6 concentrationAiTAB(12)%
C3H8 concentrationAiTAB(13)%
iC4H10 concentrationAiTAB(14)%
nC4H10 concentrationAiTAB(15)%
iC5H2 concentrationAiTAB(16)%
nC5H2 concentrationAiTAB(17)%
C6H14 concentrationAiTAB(18)%
C7H16 concentrationAiTAB(19)%
C8H18 concentrationAiTAB(20)%
C9H20 concentrationAiTAB(21)%
C10H22 concentrationAiTAB(22)%

Table 3 - Device parameters - Analogue parameter

Object descriptionValue typeAddressUnits
Analogue parameter - transducer serial No.TxtI, CiSN(ind)
Analogue parameter - upper limit of measuring rangeAiHL(ind)
Analogue parameter - lower limit of measuring rangeAiLL(ind)
Analogue parameter - technical unitsTxtIUNIT(ind)
Analogue parameter - nameTxtIDESC(ind)

Table 4 - Device parameters - Counter

Object descriptionValue typeAddressUnits
Counter - serial number of gas meterTxtI, CiSN(ind)
Counter - technical unitsTxtIUNIT(ind)
Counter - nameTxtIDESC(ind)

Table 5 - Device parameters - Error counter

Object descriptionValue typeAddressUnits
Error counter - primary counter numberTxtI, CiCNT(ind)
Error counter - technical unitsTxtIUNIT(ind)
Error counter - nameTxtIDESC(ind)

Table 6 - Device parameters - Standard counter

Object descriptionValue typeAddressUnits
Standard counter - primary counter numberTxtI, CiCNT(ind)
Standard counter - calculation numberTxtI, CiCLC(ind)
Standard counter - technical unitsTxtIUNIT(ind)
Standard counter - nameTxtIDESC(ind)

Table 7 - Device parameters - Conversion factor

Object descriptionValue typeAddressUnits
Conversion factor - analogue (pressure) numberCiCNTP(ind)
Conversion factor - analogue (temperature) numberCiCNTT(ind)
Conversion factor - pressure error volumeAiDEFVALP(ind)kPa
Conversion factor - temperature error volumeAiDEFVALT(ind)°C
Conversion factor - compressibility error volumeAiDEFVALK(ind)
Conversion factor - technical unitsTxtIUNIT(ind)
Conversion factor - nameTxtIDESC(ind)

Table 8 - Device parameters - Standard flow rate

Object descriptionValue typeAddressUnits
Standard flow rate - primary flow numberCiCNT(ind)
Standard flow rate - calculation numberCiCLC(ind)
Standard flow rate - technical unitsTxtIUNIT(ind)
Standard flow rate - nameTxtIDESC(ind)

Device microELCOR-2

Address of I/O tag can be data from column "Address" or "Default address".

Table 9 - Actual values

Object descriptionValue typeAddressDefault addressUnits
Primary volumeAiOH.1Vm3
Standard volumeAiOH.2VNNm3
Error primary volumeAiOH.3VESTm3
Error standard volumeAiOH.4VNESTNm3
Primary flow rateAiOH.5Qm3/hour
Standard flow rateAiOH.6QNNm3/hour
Compressibility ratioAiOH.7K
Actual pressureAiOH.8PkPa
Actual temperatureAiOH.9TK
Calculation numberAiOH.10Z
Device temperatureAiOH.11TPR°C
Operating value - rest (only in VF input)AiOH.12VZB

Table 10 - Service data

Object descriptionValue typeAddressDefault addressUnits
Type + serial numberTxtISE.1VCE
Serial number of temperature sensorTxtISE.2VCT
Serial number of pressure transducerTxtISE.3VCP
Version SW+HWTxtISE.4VER
Customer numberTxtISE.5CZ
Serial number of gas meterTxtISE.6PVC
Network addressTxtISE.7ADR
Constant of gas meterCiSE.8KP0=1, 1=0.1, 2=0.01, 6=100, 7=10
Measuring intervalCiSE.9IM
Interval of data sending through serial lineCiSE.10IV
Start hour of gas dayCiSE.11CD
Start of measurementTiASE.12DSM
Date and time of deviceTiASE.13DAT
Battery capacityCiSE.14BAT%
Actual statusTxtISE.15OS
Configuration bytesTxtISE.16KB
Communication rate of serial numberCiSE.17RK4=4800, 5=9600, 6=19200
CRC 51CiSE.18C1
CRC MSP 430CiSE.19C2
Battery voltageAiSE.23UPRHEXV
Display configurationCiSE.24KDIS
Bits of permission to write the itemsTxtISE.25W_RUN
Customer's regionTxtISE.26REGION
Saving interval in hourly archiveCiSE.27IU
Quantity of diff. pulses between IMP and IMP1CiSE.28IMP1_PI0=off, 255=on permanently
Input pulse ratioCiSE.32I_V_DP
Bits of record permission in RUN by a userCiSE.33WU_RUN
Actual status 2CiSE.34OS2
Setting of pulse ratio of gas meter VF on m3CiSE.35KPVF

Table 11 - Parameters

Object descriptionValue typeAddressDefault addressUnits
Base pressureAiPA.1PNkPa
Base temperatureAiPA.2PT°C
Default pressureAiPA.3PESTkPa
Default temperatureAiPA.4TEST°C
Default compressibility levelAiPA.5SK
Min. pressure limitAiPA.6PMINkPa
Max. pressure limitAiPA.7PMAXkPa
Min. temperature limitAiPA.8TMIN°C
Max. temperature limitAiPA.9TMAX°C
Limit of max. flow rateAiPA.10QMAXm3/hour
Method of compressibility calculationCiPA.11MK
CO2 concentrationAiPA.12KCO2%
N2 concentrationAiPA.13KN2%
H2 concentrationAiPA.14KH2%
Relative densityAiPA.15KD%
Heat of combustionAiPA.16KHONkWh/m3

Table 12 - Minima/maxima

Object descriptionValue typeAddressDefault addressTechnical units
Pressure under rangeAiMI.1PMMINkPa
Time of pressure under rangeTiAMI.2DPMMIN
Pressure above rangeAiMI.3PMMAXkPa
Time of pressure above rangeTiAMI.4DPMMAX
Temperature under rangeAiMI.5TMMIN°C
Time of temperature under rangeTiAMI.6DTMMIN
Temperature above rangeAiMI.7TMMAX°C
Time of temperature above rangeTiAMI.8DTMMAX
Flow rate above rangeAiMI.9QMMAXm3/hour
Time of flow rate above rangeTiAMI.10DQMMAX
Time of reset time (minima/maxima)TiAMI.11DNUL

Parameters and minima/maxima are read in period which is set in protocol parameter value Static Data Read Period.


  • Description of system μ-ELCOR and microELCOR-2 - operating schedule (Elgas 1. 6. 2006)
  • Reference books of producer ELGAS s.r.o.

Changes and modifications


Document revisions

  • Ver. 1.0 - April 22th, 2009 - creating of document.

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