VISA open seems to prevent other visa operations.

[Taylorh140]

This Image gives a better description of the problem. Opening of a new device should not affect currently running and properly operating devices. But they seem to be delayed for timeout duration.

[Taylorh140]

What do you mean by SR? 

[Taylorh140]

What do you mean by SR? (Shift register I suppose-if so done). I get the error I expected on the output (Device 1 VISA Open). 
VISA: (Hex 0xBFFF0011) Insufficient location information or the device or resource is not present in the system.

[Gaheel17]

Hi Taylorh140,

This is a known issue reported in CAR 366314. For TCP/IP instruments, the VISA Open timeout is technically not configurable, and this affects the execution of VISA Read & Write. The end result is that, when performing VISA Open on a TCP/IP instrument that can't be accessed, other VISA functions cannot execute until VISA Open finishes timing out after two seconds.

The available workaround is programmatically to check that the TCP/IP resource to open is correctly configured and available on the network, and then to only execute VISA Open in this case.

Regards,

Adolfo F.

[Taylorh140]

2 Things:

1. I think that CAR is partially fixed/changed. The VISA timeout does seem to respond properly when using VISA Open. 

2. The work around is not really a complete work around, If i have a network latency of 200ms even if the resource is available it will still halt communication on other devices for those 200ms.

For now I think the work around will be for me to use the TCP pallete instead of the VISA pallete, I was hoping this wouldn't be the case. I think that I would have to do this for the workaround anyhow. Thanks for your help Adolfo.