FB_DMXDiscUniqueBranch

This function block queries whether DMX devices are located within a certain address range. This command is used for the discovery of the connected DMX devices.

Applying a positive edge to the bStart input starts the function block, and the bBusy output goes TRUE. The inputs wLowerBoundManufacturerId, dwLowerBoundDeviceId, wUpperBoundManufacturerId and dwUpperBoundDeviceId define the address range in which DMX devices are searched. The byPortId input defines the channel within the addressed DMX device. If the execution of the command has been completed, the bBusy output goes back to FALSE. The outputs bError, udiErrorId, wReceivedManufacturerId and dwReceivedDeviceId can now be evaluated. Further positive edges at the bStart input will be ignored as long as the function block is active (bBusy is TRUE).

If there is only one DMX device in the defined address range, then the 48-bit UID of the DMX device will be returned via the outputs wReceivedManufacturerId and dwReceivedDeviceId. If no DMX devices are found in this range, the output bError is TRUE and udiErrorId is 0x8002 (no response from DMX device). If there are two or more DMX devices in the address range, bError is TRUE and udiError contains a 0x8006 (checksum error).

Inputs

VAR_INPUT
  bStart                    : BOOL;
  byPortId                  : BYTE;
  wLowerBoundManufacturerId : WORD;
  dwLowerBoundDeviceId      : DWORD;
  wUpperBoundManufacturerId : WORD;
  dwUpperBoundDeviceId      : DWORD;
  dwOptions                 : DWORD := 0;
END_VAR

Name	Type	Description
bStart	BOOL	The function block is activated by a positive edge at this input.
byPortId	BYTE	Channel within the addressed DMX device. Sub-devices are addressed through the Port Id. The root device always has the Port Id 0.
wLowerBoundManufacturerId	WORD	Unique manufacturer Id from the lower address range.
dwLowerBoundDeviceId	DWORD	Unique device Id from the lower address range.
wUpperBoundManufacturerId	WORD	Unique manufacturer Id from the upper address range.
dwUpperBoundDeviceId	DWORD	Unique device Id from upper address range.
dwOptions	DWORD	Options (currently not used).

Inputs/outputs

VAR_IN_OUT
  stCommandBuffer : ST_DMXCommandBuffer;
END_VAR

Name	Type	Description
stCommandBuffer	ST_DMXCommandBuffer	Reference to the structure for communication (buffer) with the function block FB_EL6851Communication()

Outputs

VAR_OUTPUT
  bBusy                   : BOOL;
  bError                  : BOOL;
  udiErrorId              : UDINT;
  wReceivedManufacturerId : WORD;
  dwReceivedDeviceId      : DWORD;
END_VAR

Name	Type	Description
bBusy	BOOL	When the function block is activated the output is set, and it remains active until execution of the command has been completed.
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. Only valid if bBusy is FALSE.
udiErrorId	UDINT	Contains the command-specific error code of the most recently executed command. Only valid if bBusy is FALSE (see error codes).
wReceivedManufacturerId	WORD	If the execution of the command has been completed (bBusy is FALSE), then the state of identification of the DMX device is displayed at this output.
dwReceivedDeviceId	DWORD	If the execution of the command has been completed (bBusy is FALSE), then the state of identification of the DMX device is displayed at this output.

Requirements

Development environment	required TC3 PLC library
TwinCAT from v3.1.4020.14	Tc2_DMX from 3.5.3.0