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Datalogger ESC8816 communication protocol


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


Supported device types and versions



The protocol allows reading and writing data from/into the ESC 8816 datalogger.


Implementation was performed and verified according to the ESC Model 8816 – Data Logger Engineering Manual – TIN 96-1169, August 1996 for the datalogger software version 5.02.
Starting with D2000 version 10.0.37 communication with datalogger DLX1 is supported. For this device, communication on TCP/IP-TCP line was also implemented.
Protocol is compatible also with a datalogger EDL 15 produced by ECM Monitory for which addressing of channels above 99 is supported.

Communication includes:


Table 1


Measurement typeI/O tag typeCommunication functionDocumentation
Current valuesAIPoll Most Recent Instantaneous ReadingAppendix A – A54
Current value flagsDIPoll Most Recent Instantaneous ReadingAppendix A – A54
1m averages with flagsAI, DIRetrieve AveragesAppendix A – A24
15m averages with flagsAI, DIRetrieve AveragesAppendix A – A24
30m averages with flagsAI, DIRetrieve AveragesAppendix A – A24
60m averages with flagsAI, DIRetrieve AveragesAppendix A – A24
Custom-period averages with flagsAI, DIRetrieve AveragesAppendix A – A24
Digital inputsDIPoll Current Digital Input StatusAppendix A – A19
CalibrationsAIPoll Calibration ResultsAppendix A – A22
Real time – readTOAPoll Current TimeAppendix A – A56
Real time – writeTOADownload Current TimeAppendix A – A40
Mathematic constants – writeAODownload Math Pack ConstantsAppendix A – A45
Relay outputs – writeDOUTSwitch Digital Output Control Relay On/OffAppendix A – A64


Communication line configuration



  • Communication line category: Serial, SerialOverUDP Device Redundant, TCP/IP-TCP (for DLX1).
  • Baud rate according to the ESC 8816 datalogger settings - System Configuration Screen – Baud Rate – Port 1, Baud Rate – Port 2 or Baud Rate – Port 3 according to the used datalogger port, 1 stop bit, 8 data bits, no parity.


Line protocol parameters


There can be defined the following line protocol parameters:


Table 2


KeywordFull nameMeaningUnitDefault value
PMPassive ModeEnables the passive mode (listening) of the line. Definition of the parameter PM for one station on the line is enough. In the mode, there is monitored the communication between datalogger ESC 8816 and other device (datalogger's responses to master are monitored). Listening allows to get the following types of values:
  • current values, current values' flags ("IJ" response in communication)
  • averages (1, 15, 30, 60 minute averages, custom averages) and their flags ("56" response in communication)
  • digital inputs ("23" response in communication)
  • real time - reading ("LL" response in communication)

If the passive mode has been enabled (PM=True), to disable it you must either set the parameter PM=False or restart the process D2000 KOM (i.e. deleting the parameter PM=True is not sufficient).

--
PMTPassive Mode TimeoutTimeout after expiration of which all stations changes their states to the error state, if the line is in the passive mode (see the parameter PM). If no data are received within the timeout, all the stations on the line will changes their states to the error state.sec10
DCDebug CalibrationExtended debug information for calibration data reading.-False
ACAcknowledge Calibration DataAcknowledgement of calibration data will be sent to datalogger. If acknowledgement is not sent, datalogger will repeatedly send all available calibration data.-True


Communication station configuration



  • Communication protocol: ESC 8816.
  • Station address is a decimal number within the range of 0..255. Station address must be identical with the datalogger setting System Configuration Screen – Logger ID Code.
  • Line mode number must correspond to correctly configured mode.


Station configuration is different from implementation in the versions D2000 v3.XX. There are used station time parameters (polling parameters) and polling priority, one datalogger must be divided into logical stations as follows:


  • Current values - delay - at least 1 second, station priority - 0. Current measurements of channels and digital inputs are configured on the station. Logical station with the lowest priority, the parameters delay may not be less than 1 second.
  • 1m averages – period - 1 minute, station priority - 1. There are configured 1m averages of channel measurement on the station. Logical station with a higher priority, the parameter offset couldn't be less than 5 seconds - time for datalogger for processing values.
  • 30m averages – period - 30 minutes, offset - 5..10 seconds, station priority - 2. There are configured 30m averages of channel measurements on the station. Logical station with even higher priority, the parameter offset couldn't be less than 5 seconds - time for datalogger for processing values.
  • Calibrations – stations with required period for reading calibration results.
  • For other than 1m and 30m averages (15m, 60m or custom period) averages, there must be configured the polling parameters according to adjusted average.


Note: Time of values acquired from the communication is the time of the beginning of given period. Division into individual stations is necessary to ensure data reading reliability in required time and not to overload the communication, e.g. constant acquisition of current values to the prejudice of interval averages.


Station protocol parameters


There can be defined the following station protocol parameters:


Table 3


KeywordFull nameMeaningUnitDefault value
RCRetry CountPoll repetition count in case of a communication error.-2
RTRetry TimeoutDelay between poll repetition in case of a communication error.ms1000 ms.
WFTWait First TimeoutDelay after transmitting the poll before reading the response.ms500 ms.
WTWait TimeoutDelay between response readings till its finalization.ms400 ms.
MWRMax Wait RetryRepetition count of response readings till its finalization.-8
GSIGet Stored IntervalPeriod, during which there are read archive data from the datalogger without interruption. The period is given in minutes. If the value of the period is e.g. 60 minutes, so there are read all archive data from e.g. June 3rd 1996 05:00 to 06:00, then from 06:00 to 07:00 etc. Loading archive data within the period couldn't take more than one minute, because there could be lost some current data acquired among archive readings.min10
PVProtocol VariantVariant of protocol. Existing variants are:
  • 0 - ESC8816 - standard protocol for datalogger ESC8816
  • 1 - DLX1 - support of datalogger DLX1 (implemented in august 2015 in version 10.0.37)
-0 - ESC8816


String containing the protocol parameters is being defined as follows:


Keyword=value;Keyword=value; ...


Example:


RC=1;RT=500;MWR=10;


If there is used a keyword with an invalid value in the initialization string, there will be used corresponding default value according the table 2.


I/O tag configuration



Support of communication with ESC 8816 comprises acquisition or setting of the following values:


  • reading current values with flags,
  • reading 1m, 15m, 30m or 60m averages with flags,
  • reading custom period value averages with flags,
  • reading current states of digital inputs,
  • reading calibration results,
  • reading the real time,
  • setting the real time,
  • setting mathematic constants,
  • setting relay outputs.


Current value configuration


I/O tag is AI type, measurement type is ACTUAL. Channel number is defined as a decimal number within the range of 0..99.

Note: D2000 supports extended channel addressing syntax (current values, averages, calibration results), which allows to address channels 0-359 (for datalogger EDL 15), with channels 0-99 backward compatible with standard addressing.

Configuration of current value flags


Current value flags are DI type (Digital Input). Measurement type is ACT Flag.


Note: At defining the No missing data <blank> flag, you can use the character _ (underline) for transparency.


Configuration of 1m, 15m, 30m or 60m averages


Averages are value of AI type (Analog Input). Measurement type is 1m AV for 1m averages, 15m AV for 15m averages, 30m AV for 30m averages and 60m AV“ for 60m averages. Channel number is a decimal number within the range of 0..99 (see the note about channel addressing).


Flag configuration of 1m, 15m, 30m or 60m averages


Flags of averages are values of DI type (Digital Input). Measurement type is 1mAV Flag for 1m averages, 15mAV Flag for 15m averages, 30mAV Flag for 30m averages and 60mAV Flag for 60m averages. Channel number is a decimal number within the range of 0..99 (see the note about channel addressing).


Note: At defining the No missing data <blank> flag, you can use the character _ (underline) for transparency.


Configuration of custom period averages with flags


When you define Custom AV, there is enabled to define any time period. The period must be within the range of 1..999 in the form : "sec", "min", "hour", "day". The CustomAV Flag flag do not require to define a period, they are corresponding to the AI value (average) setting for required channel (the value must be defined !).


Configuration of digital inputs


Digital inputs are values of the DI type (Digital Input). Measurement type is Digital Input. Digital input number is a decimal number within the range of 0...999.


Configuration of calibration results


Calibration results are values of the AI type (Analog Input). Measurement type is CALIB Ph1 for acquiring the value of Average During Zero value or CALIB Ph2 for acquiring the value of Average During Span1. Channel number is a decimal number within the range of 0...99 (see the note about channel addressing).


Note:
The value of Average During Span2 is also returned during reading - the value has always been -999 (invalid value) in specific application. If the value of the parameter is to be required in any other application, the protocol needs to be extended.


Real time I/O tag configuration


For each station (physically one datalogger ESC8816), there can be configured one I/O tag containing the real time of corresponding station. The I/O tag is necessary for real time synchronization computer -> datalogger.


Mathematic constant I/O tag configuration


Mathematic constants are values of the AO type (Analog Output). Measurement type is MATH. Constant number is a decimal number within the range of 0...99.
Warning
: Mathematic constants can't be read, so their current value is the value last written or unknown (after D2000 system restart).
Note: D2000 supports extended mathematic constants addressing syntax, which allows to address mathematic constants 0-359, with mathematic constants 0-99 backward compatible with standard addressing.

Relay output I/O tag configuration


Relay outputs are values of the DOUT type (Digital Output). Measurement type is Relay Output. Output number is a decimal number within the range of 0...999.
Warning
: State (value) of relay outputs can't be read, so their current value is the value last written or unknown (after D2000 system restart). Reading values is allowed by binding relay outputs with digital inputs and then to control the state of the relay outputs using the digital inputs.


I/O tag flag assignment


I/O tag flags (from A to P) are adjusted according occurrence of datalogger flags for current values, 1m averages and 30m averages as follows:


Table 3


I/O tag flagMeaningDatalogger flag
AInvalid measurement"<" or „C“, „B“, „M“, „P“ a „D“
BTransient operation"F"
CCalibration"C"
DMalfunction"B"
EMaintenance"M"
FPower cut"P"
GInactive measurement"D"
ILayoff"F"


Acquisition of archive (stored) values


The ESC 8816 datalogger executes a local archiving measured variables. The values can be requested automatically on a dispatcher system breakdown or directly by the dispatcher (D2000 HI, D2000 EventHandler) to complete the D2000 dispatcher system archive.


The method described above allows to acquire calibration values, which are 30 day old, 30m averages for last 31 days and 1m averages for the last 60 minutes.


Literature



-


Changes and modifications



  • November 1998 - Datalogger software version 5.16

    Modification – for 30m averages, there could be occurred the flag "F" (layoff) and ">" (validity of average with missing measurements), this half-hour is always considered as invalid.
    Modification - new flag "p" - layoff. Occurrence of the flag "F" is set in cases of occurrence of the flag "p" for reverse compatibility.

  • August 2000 - relay outputs writing
  • February 2003 - 15m/60m/Custom period averages


Document revisions



  • Ver. 1.2 – February 8th 2000 – Update of the versions 4.07 and 4.10.
  • Ver. 1.3 – August 22nd 2000 – controlling relay outputs added.
  • Ver. 1.4 - February 7th 2003 - custom-period averages added.
  • Ver. 1.5 - 13. mar. 2008 - Update of protocol parameters .
  • Ver. 1.6 - 26. aug. 2015 - Update of protocol parameters (protocol variant for DLX1 implemented).
  • Ver. 1.7 - 30. apr. 2018 - Enhancement of channel addressing and mathematic constants from 0-99 to 0-359.


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