Hi Steve,

60k lines = how many bytes? 2 hours may not be that unreasonable...
Do the machines report any transfer errors?
What is the distance to this CNC? What is the quality of the cable? How do you handle the switching from CNC to CNC for your program loading?
Is it possible that CNC to CNC communications are using binary or a compressed file transfer? That might explain the difference...

>I have a program that sends data via the mscomm control. I use it to send code to CNC machines, mill's lathe's etc...
>I'm now getting into files that are much longer, like 60k lines and it is taking hours to send these files. But I can send code between machines at a much faster rate. The pc is slower than the machines themselves. Even using identical baud settings.
>
>If I send a 60k line program to a cnc machine from my pc, it takes 2 hours at 38400,n,8,1. If I take that same file and send it to one cnc machine from another it takes 7 minutes. Something in my program is really slowing this communication down.
>
>I tried increasing the size of the inbuffersize & outbuffersize, but that actually made it slightly slower.