It appears even if you create more variables it will not let you connect to them or expand the express vi. I haven't seen this before. All examples that I have seen have not used as many variables as you are using. Maybe a NI person will chime in on this situation. Until that happens try using the format into string function under the string subpalette. I know this will not allow you to create a header as easily as the express vi but for your file but you can be creative and use some of the constants and string constants for a header. That is how is has been done until this new express vi has been created. Keep in mind you can also use concatenate strings and use multiple format into string functions.
BJD1613
Lead Test Tools Development Engineer
Philips Respironics
Certified LV Architect / Instructor