FB_GENIbusGetMValue

This function block reads a measured value from a GENIbus device. The operation is limited exclusively to values of class 2. Only the ID code of the high-byte and the length of the measured value need to be specified; the type of scaling and the unit of the measured value are determined by an internal INFO query. A structure at the stMValue output provides all important information about the value.

Inputs

VAR_INPUT
  bStart            : BOOL;
  byAddr            : BYTE := 0;
  byIDCode          : BYTE := 0;
  eDataSize         : E_GENIBusMDataSize;
  eCommandPriority  : E_GENIbusCommandPriority := eGENIbusCommandPriorityMiddle;
END_VAR

Name	Type	Description
bStart	BOOL	The reading process is initiated by a rising edge at this input.
byAdress	BYTE	Address of the GENIbus device to be addressed: valid entries: 1 - 200. This corresponds to the setting as is made directly on the GENIbus device. Conversion to the actual address range 32 - 231 takes place within the function block (see GENIbus standard). A broadcast command via address 255 is naturally not permitted.
byIDCode	BYTE	ID code of the value to be read. In the case of 16, 24 and 32-bit values, the ID of the high-byte must be specified here and the following order is always assumed: ID = hi, ID+1 = lo1, ID+2 = lo2, ID+3 = lo3.
eDataSize	E_GENIBusMDataSize	Data size of the measured value: 8, 16, 24 or 32 bit.
eCommandPriority	E_GENIbusCommandPriority	Priority (high, medium or low) with which the command is processed by the PLC library.

Example: Read the total volume of water pumped. For this case is:

byIdCode = 121
eDataSize = eGENIbusMSize32Bit

Source: Grundfos documentation "Operating the MAGNA3 and MGE model H/I via the GENIpro interface - Edition 01.00.35 - April 2015".

Inputs/outputs

VAR_IN_OUT
  stCommandBuffer   : ST_GENIbusCommandBuffer;
END_VAR

Name	Type	Description
stCommandBuffer	ST_GENIbusCommandBuffer	Reference to the structure for communication (buffer) with the FB_GENIbusCommunication() function block

Outputs

VAR_OUTPUT
  bBusy             : BOOL;
  bError            : BOOL;
  udiErrorId        : UDINT;
  udiErrorArg       : UDINT;
  stMValue          : ST_GENIbusMValue;
END_VAR

Name	Type	Description
bBusy	BOOL	Starting with the edge at bStart, this output remains TRUE until the command has been processed.
bError	BOOL	This output is switched to TRUE as soon as an error occurs during the execution of a command. The command-specific error code is contained in udiErrorId.
udiErrorId	UDINT	Contains the command-specific error code of the most recently executed command (see error codes). It is set back to 0 by the reactivation of the function block via the bStart input.
udiErrorArg	UDINT	If applicable, contains an extended description of the error code.
stMValue	ST_GENIbusMValue	Output of the read value.

Requirements

Development environment	PLC library to include
TwinCAT from v3.1.4020.14	Tc2_GENIbus from v3.3.0.0