ADSREADEX

The function block executes an ADS read command to request data from an ADS device. The function block has the same functionality as the ADSREAD function block; in addition it returns the number of actually read data bytes as parameter.

Inputs

VAR_INPUT
    NETID    : T_AmsNetId;
    PORT     : T_AmsPort;
    IDXGRP   : UDINT;
    IDXOFFS  : UDINT;
    LEN      : UDINT;
    DESTADDR : PVOID;
    READ     : BOOL;
    TMOUT    : TIME := DEFAULT_ADS_TIMEOUT;
END_VAR

Name	Type	Description
NETID	T_AmsNetId	String containing the AMS network ID of the target device to which the ADS command is addressed (type: T_AmsNetId).
PORT	T_AmsPort	Port number of the ADS device (type: T_AmsPort)
IDXGRP	UDINT	Index group number (32-bit, unsigned) of the requested ADS service. This value is to be found in the ADS table of the addressed device.
IDXOFFS	UDINT	Index offset number (32-bit, unsigned) of the requested ADS service. This value is to be found in the ADS table of the addressed device.
LEN	UDINT	Number of data to be read in bytes
DESTADDR	PVOID	Address of the buffer that is to receive the read data. The programmer is responsible for dimensioning the buffer such that it can accommodate LEN bytes. The buffer can be a single variable, an array or a structure, whose address can be found with the ADR operator.
READ	BOOL	The ADS command is triggered by a rising edge at this input.
TMOUT	TIME	Indicates the time before the function is canceled.

Outputs

VAR_OUTPUT
    BUSY    : BOOL;
    ERR     : BOOL;
    ERRID   : UDINT;
    COUNT_R : UDINT;
END_VAR

Name	Type	Description
BUSY	BOOL	This output remains TRUE until the function block has executed a command, but at the longest for the duration supplied to the Timeout input. While BUSY = TRUE, no new command will be accepted at the inputs. Note that it is not the execution of the service but its acceptance whose time is monitored.
ERR	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 ERRID. If the function block has a timeout error, ERR is TRUE and ERRID is 1861 (hexadecimal 0x745). Is reset to FALSE by the execution of a command at the inputs.
ERRID	UDINT	ADS error code or command-specific error code of the last executed command. Is reset to 0 by the execution of a command at the inputs.
COUNT_R	UDINT	Number of successfully read data bytes

Requirements

Development environment	Target system type	PLC libraries to include (Category group)
TwinCAT v3.1.0	PC or CX (x86, x64, ARM)	Tc2_System (System)