Ans:
After check your 2011 NC-350A1 PLC and electric connecting diagram , We found that the Y10 was add in 2016 version , Original old version which PLC no using Y10 , The wire No. 9 connect to Com- (-) , So now your connect is right , Previously we sent you is new version wire connecting diagram which with Y 10 , We forgot that we sent you is your original PLC version which no Y10 , So now is clear , You connect wire 9 direct to – is correct and it will match the PLC program 20110625 (No Y10) . ** (Attached the 2011 electric diagram for your reference)
Besides regarding the X0 input , X0 is for Guard limit switch , we remember 2011 we use push in out type switch , 2015 we use pin insert type safety door switch , Maybe there are normal open / Normal close difference , So you can check door open and door close then check X0 lamp ON or not ? while X0 lamp ON , It will allow machine work , If X0 Off , the PLC controller just prohibit the machine run. Therefore X0 ON machine working no stop is normal , While X0 is OFF the machine just stop (prohibit) the machine running. We think maybe the sensor (limit switch) of Guard which connecting is wrong , Please change the inside connecting to normal open , then X0 ON under switch press (door close) , Door open X0 should be off.
So now you connect wire 9 to – (com-) is correct (OK) and match PLC program 20110625ok.dvp , You just to check the X0 signal is right or not by testing open guard (X0 must off) and door close (X0 must ON) , If wrong , just change the inside connecting of door sensor (limit switch)