Hi, Brent -

By convention, the null (all binary zeroes) character is a terminator for the string.

Although I have not done what you are wanting to accomplish, I believe you will have to construct the data stream you are wanting to write in a PB Blob variable and pass that to the WriteFile WinAPI function. This might be tedious, as you may have to convert the string data to ANSI as you build the Blob contents, since I'm unsure whether PB will perform the Unicode 16LE to ANSI conversion on the contents of a Blob that your External Function Declaration is requesting via the ";ansi" keyword.

An alternative to consider would be to use a PB Character array and pass the array to the WriteFile API function with the ";ansi" keyword included. The Character datatype in PB is limited to Unicode only, but specifying ";ansi" may allow it to be converted. I'm not 100% positive this will work flawlessly, as the zero-character may mess things up. You'll have to experiment.

Best regards, John

Hi Bent;

  Try this example:  https://answers.sap.com/questions/11867509/readingwriting-to-com-ports.html

   Just substitute COM4 for COM1 in the able example (in your case) and for the file write operation use CHAR(0)

HTH

Regards ... Chris

I changed my program to insert the character values into a byte array and then convert the byte array to a blob and pass it into the external function, and it's working now.  Thanks a lot for your help!