Goto, OUTSTD – Signal source or output

Block SymbolsLicensing group: STANDARD

Function Description
The two blocks Goto (signal source) and OUTSTD (standard output) share the same symbol. They are used for providing signals, either internal or external.

In the function block library, you can only find the Goto block. It is converted to the OUTSTD block at compile time if necessary. The following rules define how the REXYGEN Compiler compiler distinguishes between the two block types:

• If the parameter GotoTag contains the __ delimiter (two successive ’_’ characters), then the block is of the OUTSTD type. The part (substring) of the parameter before the delimiter (DRV in the block symbol above) is considered to be the name of an IODRV type block contained in the main file of the project. The REXYGEN Compiler compiler returns an error when such block does not exist. If the driver exists in the project, the other part of the GotoTag parameter (following the delimiter, signal in this case) is considered to be the name of a signal within the appropriate driver. This name is validated by the driver and in the case of success, an instance of the OUTSTD block is created. This instance collects real-time data from the driver and feeds the data into the control algorithm at each execution of the task it is included in.
• If there is no __ delimiter in the GotoTag parameter, the block is of type Goto. A matching From block with the same GotoTag parameter for which the Goto block is visible is searched. In case it is not found, the REXYGEN Compiler compiler issues a warning and deletes the Goto block. Otherwise an "invisible" connection is created between the corresponding blocks. The Goto block is removed also in this case thus it is not contained in the resulting control system configuration.

The other parameter of the Goto block defines the visibility of the block within the given .mdl file. The TagVisibility parameter can be local, global or scoped, whose meaning is explained in the table below. This parameter is ignored if the block is compiled as the OUTSTD block.

In the case of OUTSTD block, the GotoTag parameter includes the symbol of the driver <DRV> and the name of the signal <signal> of the given driver:

• <DRV>__<signal>

E.g. the first digital output of a Modbus I/O device might be referenced by MBM__DO1. Detailed information about signal naming can be found in the user manual of the corresponding I/O driver.

Since version 2.50.5 it is possible to use placeholders in names of I/O driver signals. This is useful inside subsystems where this placeholder is replaced by the value of subsystem parameter. E.g. the flag MBM__DO<id> will refer to digital output 1, 2, 3 etc. depending on the parameter id of the subsystem the block is contained in. See the SubSystem function block for information on defining subsystem parameters.

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