viGpibControlATN
Purpose
Specifies the state of the ATN line and the local active controller state.
C Syntax
ViStatus viGpibControlATN(ViSession vi, ViUInt16 mode)
Visual Basic Syntax
viGpibControlATN& (ByVal vi&, ByVal mode%)
Resource Classes
GPIB INTFC
Parameters
| Name | Direction | Description |
|---|---|---|
|
vi |
IN |
Unique logical identifier to a session. |
|
mode |
IN |
Specifies the state of the ATN line and optionally the local active controller state. See the Description section for actual values. |
Return Values
| Completion Codes | Description |
|---|---|
|
VI_SUCCESS |
Operation completed successfully. |
| Error Codes | Description |
|---|---|
|
VI_ERROR_INV_OBJECT |
The given session reference is invalid. |
|
VI_ERROR_NSUP_OPER |
The given vi does not support this operation. |
|
VI_ERROR_RSRC_LOCKED |
Specified operation could not be performed because the resource identified by vi has been locked for this kind of access. |
|
VI_ERROR_NCIC |
The interface associated with the given vi is not currently the controller in charge. |
|
VI_ERROR_INV_MODE |
The value specified by the mode parameter is invalid. |
|
VI_ERROR_NSUP_MODE |
The specified mode is not supported by this VISA implementation. |
Description
This operation asserts or deasserts the GPIB ATN interface line according to the specified mode. The mode can also specify whether the local interface should acquire or release Controller Active status. This operation is valid only on GPIB INTFC (interface) sessions. The following table lists valid values for the mode parameter.
| Mode | Action Description |
|---|---|
|
VI_GPIB_ATN_DEASSERT |
Deassert ATN line. The GPIB interface corresponding to the VISA session goes to standby. |
|
VI_GPIB_ATN_ASSERT |
Assert ATN line and take control synchronously without corrupting transferred data. If a data handshake is in progress, ATN is not asserted until the handshake is complete. |
|
VI_GPIB_ATN_DEASSERT_HANDSHAKE |
Deassert ATN line, and enter shadow handshake mode. The local board participates in data handshakes as an Acceptor without actually reading the data. The GPIB interface corresponding to the VISA session goes to standby. |
|
VI_GPIB_ATN_ASSERT_IMMEDIATE |
Assert ATN line and take control asynchronously and immediately without regard for any data transfer currently in progress. Generally, this should be used only under error conditions. |
It is generally not necessary to use the viGpibControlATN() operation in most applications. Other operations such as viGpibCommand() and viGpibPassControl() modify the ATN and/or CIC state automatically.
Related Topics