power-on UNO(r3) with W5200 ethernet shield(V2.4) problem?

I bought the Arduino UNO r3 and W5200 ethernet shield v2.4 .And then connect them.When I upload the code on it, the network work well.But when I power off ,then power-on it.I found its network function not work.I need to click reset key,then it work. I don't know what's problem? its w5200 ethernet shield's problem? How to solve it?

It seems some ethernet shields have problems with restarts. I have a w5100 shield, and it does ok. It has a reset pulse extender that takes care of the problem you describe. Here is a link to a pic of the w5100 board. Next to the crystal can and underneath the word "SHIELD" is the reset IC. It is a small 4 pin surface mount chip.

Post a link to your ethernet shield and I'll try to help.

I bought this ethernet shield. http://www.seeedstudio.com/wiki/Ethernet_Shield_V2.4#Example_3:_Control_The_Arduino.27s_Digital_Pins_From_a_Webpage_Served_by_The_Shield

I didn't find a schematic, so I don't know about the reset IC. You are using the library from the Seeed Studio's Github site, correct?

The w5200 may take a bit longer to start than the w5100. Try adding a small delay in your setup function before initializing the w5200. Maybe 500ms or so.

Do you have a SD card in the shield's SD slot?

SurferTim:
It seems some ethernet shields have problems with restarts. I have a w5100 shield, and it does ok. It has a reset pulse extender that takes care of the problem you describe. Here is a link to a pic of the w5100 board. Next to the crystal can and underneath the word "SHIELD" is the reset IC. It is a small 4 pin surface mount chip.
http://arduino.cc/en/Main/ArduinoEthernetShield

Post a link to your ethernet shield and I'll try to help.

Thanks for your help! I bought a w5200 ethernet shield(you can see this link http://www.seeedstudio.com/wiki/Ethernet_Shield_V2.4#Example_3:_Control_The_Arduino.27s_Digital_Pins_From_a_Webpage_Served_by_The_Shield ).I think it can not properly reset on power-up.I don't know how to solve this problem.Please give me any idea.Thanks!

I saw the pic, but not a schematic.

I gave you two ideas.

  1. Use a delay(500) call in setup before starting the w5200.
  2. If you have a SD card in the shield's slot, remove it.

I add the delay code to setup() and remove SD card. But it not work. You want to get the schematic (http://www.seeedstudio.com/wiki/File:W5200_Datasheet.pdf). I think it must be it.Thanks!

That link is to the datasheet for the Wiznet w5200 ethernet controller, not the ethernet shield schematic.

you mean my really connect picture? i just connect uno and ethernet shield, then connect usb to pc and rj45 to ethernet port.that,s all.

my connection is very simple and clearly, do you need my code?