ASRL_WIRE_MODE

[Wolfgang]

Hi,

Using VISA, at program startup I am querying all available ports (for access and properties). In order to distinguish between RS232 and RS485 I use the attribute VI_ATTR_ASRL_WIRE_MODE.

Surprisingly, the call returns VI_ASRL_WIRE_485_4 although the port definitely is RS232, this is also confirmed by reading the port description which says: NI PCI-8430/8 (RS232).... (in accordance with NI-MAX)

The original software has been developed with CVI 8.5; since I recently upgraded from VISA 5.3 to 5.4 I suspect some incompatibility, could it be...?

Some other software is also running on the same computer so the run time engine is CVI2013.

Thanks!

[Wolfgang]

Using VISA, at program startup I am querying all available ports (for access and properties). In order to distinguish between RS232 and RS485 I use the attribute VI_ATTR_ASRL_WIRE_MODE.

Surprisingly, the call returns VI_ASRL_WIRE_485_4 although the port definitely is RS232, this is also confirmed by reading the port description which says: NI PCI-8430/8 (RS232).... (in accordance with NI-MAX)

The original software has been developed with CVI 8.5; since I recently upgraded from VISA 5.3 to 5.4 I suspect some incompatibility, could it be...?

Some other software is also running on the same computer so the run time engine is CVI2013.

[Wolfgang]

Thanks!

[Wolfgang]

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@Wolfgang wrote:

Hi,

Using VISA, at programstartup I am querying all available ports (for access and properties). In order to distinguish betweenRS232 andRS485 I use the attribute VI_ATTR_ASRL_WIRE_MODE.

Surprisingly, the call returns VI_ASRL_WIRE_485_4 although the port definitely is RS232, this is also confirmed by reading the port description which says: NI PCI-8430/8 (RS232).... (in accordance with NI-MAX)

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I just have learned that this is a 'known' bug in VISA 5.4

[Wolfgang]

Using VISA, at programstartup I am querying all available ports (for access and properties). In order to distinguish betweenRS232 andRS485 I use the attribute VI_ATTR_ASRL_WIRE_MODE.

Surprisingly, the call returns VI_ASRL_WIRE_485_4 although the port definitely is RS232, this is also confirmed by reading the port description which says: NI PCI-8430/8 (RS232).... (in accordance with NI-MAX)