cable to do what?

TTFN

it is to plc network communication.Data quality is very important for the system. SO wish to find out the comparison

But what's the environment and distance, etc?  You've started out by asking the last question in a chain.  What are the requirements of the "data quality?"  A standard network protocol such as TCP/IP has some error detection to correct erroneous transmission.  You can always encode your data for additional error correction and use twisted-shielded, if that's the overall proper solution.

The "best" cable is question is requires knowing what the "best" solution is for your particular application.  For example, fiber requires transceivers on both ends as added costs.  Is cost not relevant?

TTFN

If you are networking two or more PLC's together using Ethernet (i.e TCP/IP, UDP) use a good quality Plenum rated  CAT-5E, UTP, 24 guage. BERK-TEK makes a good cable, but any manufacturers cable will suffice (as long as it is CAT-5E UTP). Cabling specifications state that the cable is fully rated to 100Mbit out to 100M (330 ft).
If you require longer distances, go with multi-mode fiber. MM fiber is good up to 2Km, depending on the ehrtnrt to fiber interface you choose.