FB_VN_ReadMemory

This FB reads consecutive memory locations from the camera. Requires an open control channel (e.g. by calling FB_VN_GevCameraControl.OpenCamera() before)

Syntax

Definition:

FUNCTION_BLOCK FB_VN_ReadMemory
VAR_INPUT
    nAddress                 : GVCP_REGISTER_ADDRESS;
    nLength                  : UINT;
    pBuffer                  : PVOID;
    bRead                    : BOOL;
    nTimeout                 : TIME;
END_VAR
VAR_OUTPUT
    bBusy                    : BOOL;
    bError                   : BOOL;
    nErrorId                 : UDINT;
END_VAR
VAR
    oidITcVnGevImageProvider : OTCID;
END_VAR

Inputs

Name	Type	Default	Description
nAddress	GVCP_REGISTER_ADDRESS		The address of the first byte to read from the camera (must be 32-bit aligned)
nLength	UINT		The number of bytes to read, starting with nAddress (must be a multiple of 4, not more than 536)
pBuffer	PVOID		Pointer to the buffer where the read memory content is written to (The buffer must have a size of at least nLength bytes!)
bRead	BOOL		Reading the memory is triggered by a rising edge at this input.
nTimeout	TIME	VISION_ADS_TIMEOUT	Indicates the time before the function is cancelled.

Outputs

Name	Type	Description
bBusy	BOOL	This output remains TRUE until the function block has executed a command, but at the longest for the duration supplied to the 'nTimeout' input. While bBusy = TRUE, no new command will be accepted at the inputs.
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 ‘nErrorId’. If the function block has a timeout error, 'bError' is TRUE and 'nErrorId' is 1861 (hexadecimal 0x745). Is reset to FALSE by the execution of a command at the inputs.
nErrorId	UDINT	Contains the ADS error code or the command-specific error code of the last executed command. Is reset to 0 by the execution of a command at the inputs.

Weiterführende Informationen

	Offener Kamera-Control-Channel nötig! Um diesen Funktionsblock benutzen zu können, muss der Control Channel der GigE Vision Kamera offen sein. Zudem können einige Kamera-Parameter nur geändert werden, wenn die Bild-Akquisition gestoppt ist. Daher wird empfohlen, die Kamera zuvor in den State TCVN_CS_OPENED zu bringen.

Parameter

nAddress

Die Register-Adresse identifiziert das zu adressierende Register der Kamera. Sie ist vom Typ GVCP_REGISTER_ADDRESS, welcher ein Alias auf den Typ UDINT ist. Damit haben alle Register-Adressen eine Größe von 4 Bytes. Die Register-Adresse eines Kamera-Parameters können Sie an entsprechender Stelle im Konfigurationsbaum der GigE Vision Kamera Instanz nachsehen:

Required License

TC3 Vision Base

System Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT V3.1. 4024.44 or later	PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU	Tc3_Vision