Looking for help with knitting machine terms
This is my understanding of the terms:

起始针 - starting stitches (the first row)

花样 - pattern

花板 - most likely pattern template

花版最大幅 - the largest (widest) part of the pattern template

设定总针数 - pre-set total number of stitches

The sentence you quote sounds like an awkward translation of the following:

When the number of stitches at starting + stitches at largest part of the pattern exceeds the total number pre-set by the knitting bed, a warning signal will pop up.

Now I have to admit I've never used a knitting machine before, but I have been knitting since I was nine years old, so I feel I can probably shed some light on this. It makes sense that a machine will need to have a limit on how big a garment and how complicated a pattern it can produce. If my understanding is correct, you probably don't need to worry about this part, unless you're trying to knit something really, really enormous or have an extraordinarily complex pattern.