VISA Serial settings not being set?

[RTSLVU]

I have an issue with VISA and LabVIEW 2023 Q1. 

I have several test systems, one in particular has an instrument that uses serial where the rest of the systems use GPIB or LXI for that instrument.

This program and test system has been running fine but I am in the process of upgrading to LV 2023 while I add a couple requested features. 

Nothing in my find and initialize sub vi has changed, all 7 other test systems run fine with the new LV 2023 program.  

Both NI-Max and Windows Device Manager show the proper serial settings. (115200,8,N,1,hardware flow control).

But all serial communications in my program time out and the probe window shows the serial setting are the default (9600,8,N,1,No flow control)

What's going on here?

[santo_13 · Accepted solution]

Another post had the same issue, there I read that VISA resets all external configurations at initialize.

[RTSLVU]

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@santo_13 wrote:

Another post had the same issue, there I read that VISA resets all external configurations at initialize.

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Previous versions of NI-VISA must have used the setting in NI-MAX as the "default" for that serial port if VISA Set Serial was not used

[rolfk]

VISA Open has an access mode input parameter.

This is really a bitmask:

1: Exclusive Lock

4: Load Configuration Settings

Default is to use the VISA default values (none of the flags is set). And these default values are session type specific default values, not what you configure in NI-MAX or any VISA config or similar utility per individual port.