Connection Responsiveness:Information Method
Short Name: Conn Responsive.Info
Installed With: Base Package
Class: Application Methods
Gets and sets how often LabVIEW checks if a VI Server connection is responsive.
Set the PingDelay and PingTimeout parameters of this method to configure how LabVIEW checks the connection. If LabVIEW does not receive a message in the time you specify in PingDelay, LabVIEW sends a query to prompt the VI Server network connection for a message. After sending the query, if LabVIEW does not receive a message in the time you specified in PingTimeout, LabVIEW considers the connection unresponsive. Then, all VIs and functions waiting on the connection return a network connection error.
For example, if you set PingDelay to 3000 and PingTimeout to 1000, LabVIEW sends a query to verify the status of the VI Server network connection every time 3 seconds elapse without LabVIEW receiving a message over the connection. If LabVIEW does not receive a reply from the network, LabVIEW waits 1 second before all VIs and functions waiting on the connection return network connection error 1130, which you can handle on the block diagram.
Default for PingDelay and PingTimeout is 10,000 ms, which means LabVIEW checks the connection every 10 seconds and waits up to 10 seconds for the connection to respond.
 | Note If a network operation times out according to the timeout value you specify in PingTimeout, LabVIEW considers the connection unresponsive but does not close the connection. All current and future calls waiting on the connection return a connection error. LabVIEW does not send another message to query the connection status until LabVIEW considers the connection responsive again. A connection becomes responsive again when LabVIEW receives a message over the connection. |
Parameters
| Name | Required | Description |
|---|---|---|
| PingDelay | No | Specifies how long between queries LabVIEW waits, in milliseconds. If you specify a value of –1 (infinity) LabVIEW does not check the connection unless you use the Connection Responsiveness:Check method. If you want LabVIEW to check the connection, you must set PingDelay to a positive number or use the Connection Responsiveness:Check method. |
| PrevPingDelay | No | PingDelay in milliseconds you previously specified. |
| PingTimeout | No | Specifies how long in milliseconds before LabVIEW times out after LabVIEW sends a query to prompt the VI Server network connection for a message. If a timeout occurs, all VIs and functions waiting on the connection return a connection unresponsive error. |
| PrevPingTimeout | No | PingTimeout in milliseconds you previously specified. |
Remarks
The following table lists the characteristics of this method.
| Available in Run-Time Engine and Real-Time Operating System | Yes (Read/Write) |
| Settable when the VI is running | No |
| Loads the front panel into memory | No |
| Need to authenticate before use | No |
| Loads the block diagram into memory | No |
| Remote access disallowed | No |
| Must wait until user interface is idle | No |
| Available with control VIs | No |
| Available with global VIs | No |
| Available with strict type definitions | No |
| Available with polymorphic VIs | No |
Examples
Refer to the following VIs for examples of using the Connection Responsiveness:Information method:
- Manual VI Server Connection Polling VI: labview\examples\viserver\connpolling.llb
Open example Browse related examples - Automatic VI Server Connection Polling VI: labview\examples\viserver\connpolling.llb Open example Browse related examples