又看了一些国外的论坛，有人问过这个问题，我估计redef也不能解决这个问题，死心了，老老实实用GUD变量
Hello everyone!I have a problem with sharing R parameters between 2 channels on a machine with an 840D. I wonder if there is a * way to access R parameters in the second channel from a NC program running in the first?Best regards, Kajan.
Since the R variables are channel-specific, I don't think it is possible to read another channel's R variables.

You can create your own array using a global GUD (use the NCK keyword) that is common to both channels. For example, in UGUD.DEF, place the line:

DEF NCK REAL GR[100]

If look-ahead is an issue, you can either use STOPRE to stop block look ahead, or use the SYNRW keyword in the definition line to stop look ahead at all references to the variable.

Hope this helps,
SteveA