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titleFile location

<WorkspaceDirectory>\DataFiles\xio.Modbus.DatapointDefinitions.dat

The Modbus interface provides the opportunity to read and write Modbus datapoints. The current version of the NETx BMS Core Server 4.0 support supports the handling of Modbus discrete inputs, coils, holding registers, and input registers. 

The encoding of Modbus datapoint types is vendor-specific. To be able to deal with the different vendor-specific encoding, configuration parameters to set the swapping of Words, Double Words, and Bits are available. These parameters can be defined for each device and for each datapoint. Furthermore, it is possible to specify the endianess that is used within the device.

Note that using the correct encoding settings is at utmost importance. If these parameters are incorrect, the corresponding values of the Modbus datapoints are interpreted, stored, and displayed in a wrong way. Furthermore, it has to be considered that these parameters are affecting each other. To choose the correct parameters please refer to the manual and datasheet of the used Modbus devices.

The structure of the Modbus datapoint definition file is as follows: ' Modbus datapoint configuration file
' DeviceName;ModbusType;Address;SubDataType;Size;Description;PollingInterval;Persistent;Historical;Synchronize; Wordswap;DWordswap;Bitswap
ModbusController1;discrete input;12416;bool;1;DI 1;10;F;F;F;F;T;F
ModbusController1;coil;12417;bool;1;DO 1;10;F;F;F;;;;;
ModbusController1;input register;12418;uint16;1;AI 1;10;F;F;F;F;;;;;
ModbusController1;holding register;12419;uint16;1;AO 1;10;F;F;F;F;;;;;
Each line – except comment lines that start with ' – defines a single Modbus datapoint.

 

  Parameter  Description1DeviceName This attribute refers to the name
 Col# Parameter DescriptionScopeUnitDefault
1Device nameName of the device which holds the datapoint. This name must match the device name used in the Modbus device
configurationThis parameter refers to the datapoint type.
definition.


2
ModbusType This attribute defines
Modbus DP typeData type of the data point.Modbus datapoint type

3Address
 
Specifies the memory address of the Modbus
datapointThis identifier specifies
register.


4
SubDataType 
Data typeSpecifies the data type of Server Item that shall represent
the
the Modbus
datapointThis identifier specifies
data point.


5Size
 
Specifies the size of the Modbus
datapoint This attribute can
data (only considered if DataType is set to "string" or "wstring").
byte
6Description
 
Can be used to specify a human-readable text that further describes the
datapointThis parameter specifies
data point. Optional.


7
PollingInterval 
Polling intervalSpecifies the interval that is used to poll the value of the
datapointThis parameter specifies
data point.


8Persistent
 
Specifies whether the value of the datapoint is persistent (restored from the database after server start up ) or not.
9
boolean
Historical This parameter specifies whether historical values of the datapoint are stored within the database or not.

F
10Synchronize
 If this parameter is set to "T", the

Specifies the synchronization behavior in a Main/Backup setup.

  • T: the value is synchronized between the main and backup server
(if present). This will work only if synchronize is enabled in the NMESH configuration of the NETx BMS Core Server.
  • .
  • T: the value is not synchronized between the main and backup server.
boolean
T
11Wordswap
 This parameter can
Can be used to overwrite the Word Swap parameter of the Modbus device. If this parameter is set to "T" ("TRUE") or "F" ("FALSE"), the word swapping for this datapoint is overwritten. If this parameter is empty (or set to a value unequal to "T" or "F"), the word swapping specified in the device definition is used.


12DWordswap
 This parameter can This parameter can
Can be used to overwrite the Double Word Swap parameter of the Modbus device. If this parameter is set to "T" ("TRUE") or "F" ("FALSE"), the double word swapping for this datapoint is overwritten. If this parameter is empty (or set to a value unequal to "T" or "F"), the double word swapping specified in the device definition is used.


13Bitswap
 
Can be used to overwrite the Bit Swap parameter of the Modbus device. If this parameter is set to "T" ("TRUE") or "F" ("FALSE"), the bit swapping for this datapoint is overwritten. If this parameter is empty (or set to a value unequal to "T" or "F"), the bit swap specified in the device definition is used.


14Read on Reconnect
 
If
this parameter is
set to "T", a read request is sent
The default value is "T".
if the connection status of the gateway changes to ONLINE.boolean
F
15Write Mode
 
If not specified, the write mode that is defined within the Modbus Device Definition is used.

 

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