Wait for GPIB RQS Function

Owning Palette: GPIB Functions

Requires: Base Development System

Waits for the device indicated by address string to assert RQS.

Use the GPIB Wait function to wait for a specified device to assert any state.

Refer to GPIB Function Defaults for more information about the timeout and address defaults.

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address string contains the address of the GPIB device with which the function communicates. You can input both the primary and secondary addresses in address string by using the form primary+secondary. Both primary and secondary are decimal values, so if primary is 2 and secondary is 3, address string is 2+3.

If you do not specify an address, the functions do not perform addressing before they attempt to read and write the string. They assume you have either sent these commands another way or that another controller is in charge and therefore responsible for the addressing. If the controller is supposed to address the device but does not do so before the time limit expires, the functions terminate with GPIB error 6 (timeout) and set bit 14 in status. If the GPIB is not the Controller-In-Charge, do not specify address string.

When there are multiple GPIB controllers that LabVIEW can use, a prefix to address string in the form ID:address (or ID: if no address is necessary) determines the controller that a specific function uses. For example, to set GPIB controller 2 to talk to a device on address 3, use the prefix 2:3. If a controller ID is not present, the function defaults to controller (or bus) number 0.
timeout ms specifies the time, in milliseconds, that the function waits before timing out. To disable timeouts, set timeout ms to 0. The operation aborts if it does not complete within timeout ms.

To use the 488.2 global timeout, leave timeout ms unwired or set the input to –1. Then use the SetTimeOut function to change the default value of timeout ms. The default is 10000.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
poll response byte returns the serial poll response from the specified device. If SRQI is set, the function polls the device at the specified address to see if the device requested service. When the specified device requests service (the RQS bit—bit 6 in the device's Status Byte Register—is TRUE), the function returns the serial poll response.

If the device indicated by address string does not respond within the timeout limit, poll response byte is –1.

Note  The bit definitions for the poll response byte vary among instruments.
error out contains error information. This output provides standard error out functionality.