Using digital and analog signals in the same cable
But there would be analog and digital signals in the same cable. Is
this a problem ?

It can be a problem depending on the nature of the signals, the type and length of the cable, and what's at either end.  In other words, there are many variables.

If so, what are the solution to transmit digital and analog signals at
the same time ?


Use cable that shields sensitive signals from one another.
Use techniques like differential pairs, input buffers, etc.

There is no single solution that can be applied to all circumstances.
It appears you are using RS-485.  That signaling system was designed to drive long cables.  You mention &quot;supply&quot; and I assume you mean power supply.  The biggest concerns there are wire gauge so that the far-end voltage is adequate to supply the need.