Help me Profinet !!!!!!

Hi everybody!
I'm using a CPU 319 3PN-DP (318-3EL00-0AB0) to establish a simple communication with my PC. I have read the example for configuring PROFINET network using a CPU 317 2PN-DP. This requires a SCALANCE in which a PC and a CPU 317 2PN-DP plugged. Is it the same with CPU 319 3PN-DP. I have linked directly my PC to the CPU by an ETHERNET cable. Power supply had been switched on before. However, nothing happened. The symptoms are: the DC 5V on the CPU was ON, the STOP Led blinked every approx 2 seconds and my PC reported: 'network cable is unplugged'.
I hope to hear from u soon!
Kind regards,

When it says "network cable unplugged" it is most probably because the PC and the PLC dont autonegotiate MDI/MDIX.
I find that sometimes this works and sometimes not. It seems to depend on the PC.

There are two remedies:
Use a crossed ethernet cable in stead of a straight cable.
Or, place an ethernet switch between the PC and the PLC. Almost every switch autonegotiate by default.

edit: Of course the cable may be defective.
Here it is nice with a switch. There are lamps on the switch for each port, so you can immediately observe if a connection on a port is OK.

First of all, i'm very pleased to receive your reply soon, Jesper. I forgot telling you that, I have used a crossover cable already. It has 4 pins(1,2,3 and 6) on each terminal. Pin1 of one terminal was connected to Pin 3 of the other one and vice versa. Also, pin 2 of one terminal was connected to pin 6 of the other one and vice versa. Is it the right way to form a crossover cable??

I also carefully tested the wiring by a meter. However, in my opinion, there's must be smthing wrong with my Ethernet card because when I unpluged the cable and then connect my computer to the Internet again, everything was OK as if nothing happened.

My friend! Have u ever undergone this situation? I long for your assisstant! Thanks you for your help.
With kind regards,
Your friend.

Hi again phaothu.

Crossed cable is OK. 1-3, 3-1, 2-6, 6-2.
It does sound as a problem with MDI/MDIX autonegotiation.
If you tried a crossed cable, then try to switch to a straight cable.
Or, try to connect a switch between the PC and the PLC.

Hi Jesper! I want to say that my trouble has been eased comparatively after receiving your suggestion. This time I monitor the Link Led on the CPU while remaining all configuration( crossover cable directly linked PC to CPU). Fortunely, the result released the wrinkles on my forehead. The Link Leds on both terminals are lit and PC announced 'network connected'.

However, there's still smt existing in my system. The announcement 'network connected' did not last so long (about 10 sec). Sometimes, Link Leds shifted to "OFF" along with the 'network cable unplugged' statement on the PC. Then, Link Leds turned "ON" together with 'network connected' on PC. So, I cannot perform download to PLC and access to PLC.

I appreciate your valuable supports.
Help me again, please, my patient friend!
With best regards,

Sounds as something is defective.
Try to change the cable.
Try to use a switch.
Try another PC.

Hi Jesper,
I have attempted to use your approach. I tried the switch SCALANCE X005 and a new cable (this time is straight PROFINET cable). Things got much more better. All Led Links lit permanently (on both PC and CPU). However, when I downloaded my HW configuration into the CPU, I cannot view the CPU when I click the View button in the Accessible Nodes dialog.

According to an example in a manual I've read, MAC address have to appear in the Acessible Nodes part if everything is OK. I think all the hardware is OK! So I am very concerned about this.

Could you explain to me why??
Thanks for your valuable supports !
I hope to hear from u soon, friend.
With kind regard,
Hoang Viet

After you downloaded the HW Config, can you ping the PLC ?
What are the IP addresses of PC and PLC ?

I intend to download my HW configuration to the CPU for the first time. So it is impossible for me to ping the CPU because I can ping to the CPU only when the CPU have had it own IP address already.
What should I do now?

OK, I think I know what is your problem now. You cannot get to the point where you download the HW Config.

S7ONLINE in Set PG/PC Interface must be set to TCP/IP.
Start downloading from the HW Configuration.
A dialog will appear where it suggest you download to the IP address as is set to the CPU in the project. But the IP has not yet been set, so now what, a catch-22 ? Solution: In the same dialog, there is a button "View", click it and wait. After some time, the connected CPU shall appear by its MAC address and with the name "S7-300". Select it and start downloading.

If succesful, you shall now be able to ping the CPU and go online via ethernet.

Hi Jesper!
I want to announce that I eventually gained success. I was able to download my HW configuration to the CPU via Profinet following your instructions.
Thanks very much for your patience and enthusiasm. I appreciate your valuable support.
Goodbye friend, see you again!
Best regards,
Hoang Viet.