The wiring length between the PHX400 and the target board depends
on the drive capability of the target microcomputer and the communication baud rate,
so it is not possible to say how far the wiring can be extended, so there is no particular limitation.
In our evaluation at the time of developing the microcomputer pack,
we have confirmed that it usually works with the discrete wire (300mm)attached to the PHX400.
If you use a wire other than the one attached to the PHX400,
please verify the operation with your equipment in advance.