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 the handling of Modbus discrete inputs, coils, holding registers, and input registers. For more information see Section 4.9.3.
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 (cf. Section 4.3.2.1).
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.
1 | DeviceName | This attribute refers to the name of the device which holds the datapoint. This name must match the device name used in the Modbus device configuration. | |
2 | ModbusType | This parameter refers to the datapoint type. Valid types are defined in Section 4.9.3. | |
3 | Address | This attribute defines the memory address of the Modbus datapoint. | |
4 | SubDataType | This identifier specifies the data type of Server Item that shall represent the Modbus datapoint. Valid sub types are defined in Section 4.9.3. | |
5 | Size | This identifier specifies the size of the Modbus datapoint (only considered if DataType is set to "string" or "wstring", see Section 4.9.3. | |
6 | Description | This attribute can be used to specify a human-readable text that further describes the datapoint. | |
7 | PollingInterval | This parameter specifies the interval that is used to poll the value of the datapoint. | |
8 | Persistent | This parameter specifies whether the value of the datapoint is persistent (restored from the database after server start up ) or not. | |
9 | Historical | This parameter specifies whether historical values of the datapoint are stored within the database or not. | |
10 | Synchronize | If this parameter is set to "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. | |
11 | Wordswap | This parameter 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. | |
12 | DWordswap | This parameter 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. | |
13 | Bitswap | This parameter 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. | |
14 | Read on Reconnect | If this parameter is set to "T", a read request is sent The default value is "T". | |
15 | Write Mode | If not specified, the write mode that is defined within the Modbus Device Definition is used. |