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AT Command Tutorial-EN

Example 1. Data communication in Static IP and TCP Server mode​

1. Set WIZ550SR with Static IP

Set Network IP(192.168.3.101), Subnet Mask(255.255.255.0) and Gateway(192.168.3.1) of WIZ550SR

<TX> AT+NSET=S,192.168.3.101,255.255.255.0,192.168.3.1\r\n
<RX> [S]\r\n

If you check with AT+NSTAT command after above command, you can get response like below.

<TX> AT+NSTAT\r\n
<RX> [S,,S,192.168.3.101,255.255.255.0,192.168.3.1,168.126.63.1]\r\n

2. Set operating mode of WIZ550SR with TCP Server mode whose port number is 5000

Create a socket in WIZ550SR with local port number 5000

<TX> AT+NOPEN=S,5000\r\n
<RX> [S]\r\n

You can check the current status of the socket which you made with AT+NSOCK. Below is an example of it.

<TX> AT+NSOCK=0\r\n
<RX> [S,,S,5000]\r\n

3. a TCP Client connects to WIZ550SR

When A TCP Client of PC(or any Device) PC connected to WIZ550SR , you will get a message from WIZ550SR like below

<RX> [V,0,0]\r\n

4. Send data to TCP Client

If you send 5 bytes data "Hello" to TCP Client with AT+NSEND like below, you will get two step response, Wait Response and Success Response.
[W, 0] means that WIZ550SR recognized and is processing the command but it is not completed yet. And '0' means socket ID.

<TX> AT+NSEND=0,5\r\nHello
<RX> [W,0]\r\n[S,0]\r\n

5. Receive data "Hi" from TCP Client

If TCP Client sends 2 bytes data "Hi", then you will get response from WIZ550SR like below

<RX> [R,0,2]\r\nHi\r\n

6. Disconnect current TCP connection

Do send command like below to disconnect current connection.

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n

After above command, if you check the status of socket with AT+NSOCK command then you will get response like below.

<TX> AT+NSOCK=0\r\n
<RX> [S,,I]\r\n

Appendix
Changing mode from Data mode to Coomand mode

<TX> +++
<RX> \r\n\r\n\r\n[W,0]\r\n[S,0]\r\n (20 Byte)

Changing mode from Command mode to Data mode

<TX> AT+MDATA\r\n
<RX> [S]\r\n (5 Byte)

Example 2. Retrieving web page of www.google.com in Dynamic IP and TCP Client mode​

1. Set WIZ550SR with Dynamic IP

Set WIZ550SR with Dynamic IP.

<TX> AT+NSET=D\r\n
<RX> [S]\r\n

If you check with AT+NSTAT command after above command, you can get response like below.

<TX> AT+NSTAT\r\n
<RX> [S,,D,192.168.3.101,255.255.255.0,192.168.3.1,168.126.63.1]\r\n

2. Get IP address of www.google.com

Obtain IP address of www.google.com by DNS function like below command.

<TX> AT+FDNS=www.google.com\r\n
<RX> [S,,173.194.126.168]\r\n

3. Connect to google web server

Make TCP Client socket to connect to google.com.
AT+NOPEN needs Server's IP address not Domain name, so you should put IP address which you got by above command AT_FDNS
You can see that local port number was not written.
If you don't write local port number, local port number will be allocated dynamically by WIZ550SR.

<TX> AT+NOPEN=C,,173.194.126.168,80\r\n
<RX> [W,0]\r\n[S,0]\r\n

You can check the current status of the socket which you made with AT+NSOCK. Below is an example of it.

<TX> AT+NSOCK=0\r\n
<RX> [S,,C,2014,173.194.126.168,80]\r\n

4. Send data to google web server

Let WIZ550SR send 18 bytes data to google.com with below command

<TX> AT+NSEND=0,18\r\nGET / HTTP/1.1\r\n\r\n
<RX> [W,0]\r\n[S,0]\r\n

5. receive data from google.com

If WIZ550SR receives data from google.com, you can know its data size and data like below.

<RX> [R,0,523]\r\nHTTP/1.1 302 Found\r\nCache-Control: private\r\nContent-Type: text/html; charset=UTF-8\r\n..............

6. Disconnect current TCP connection

Do send command like below to disconnect current connection.

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n

Example 3. Data communication with more than two servers in Dynamic IP​

1. Set WIZ550SR with Dynamic IP

Set WIZ550SR with Dynamic IP.

<TX> AT+NSET=D\r\n
<RX> [S]\r\n

If you check with AT+NSTAT command after above command, you can get response like below.

<TX> AT+NSTAT\r\n
<RX> [S,,D,192.168.3.101,255.255.255.0,192.168.3.1,168.126.63.1]\r\n

2. Connect to the first TCP Server

If the first TCP Server's IP address is 192.168.3.201, its port number is 5000 and local port number is 2010, then You can send a command like below.

<TX> AT+NOPEN=C,2010,192.168.3.201,5000\r\n
<RX> [W,0]\r\n[S,0]\r\n

You can check the current status of the socket which you made with AT+NSOCK. Below is an example of it.

<TX> AT+NSOCK=0\r\n
<RX> [S,,C,2010,192.168.3.201,5000]\r\n

3. Send data to the first TCP Server

Send 10 bytes data to the first TCP Server like below.

<TX> AT+NSEND=0,10\r\n1111111111
<RX> [W,0]\r\n[S,0]\r\n

4. Disconnect the connection with the first TCP Server

Do below command in order to disconnect current connection.

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n

5. Connect to the second TCP Server

If the second TCP Server's IP address is 192.168.3.202, its port number is 5000 and local port number is 2011, then You can send a command like below.

<TX> AT+NOPEN=C,2011,192.168.3.202,5000\r\n
<RX> [W,0]\r\n[S,0]\r\n

6. Send data to the second TCP Server

Send 10 bytes data to the second TCP Server like below.

<TX> AT+NSEND=0,10\r\n2222222222
<RX> [W,0]\r\n[S,0]\r\n

7. Disconnect the connection with the second TCP Server

Do below command in order to disconnect current connection.

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n

8. Connect to the third TCP Server

If the third TCP Server's IP address is 192.168.3.203, its port number is 5000 and local port number is 2012, then You can send a command like below.

<TX> AT+NOPEN=C,2012,192.168.3.203,5000\r\n
<RX> [W,0]\r\n[S,0]\r\n

9. Send data to the third TCP Server

Send 10 bytes data to the third TCP Server like below.

<TX> AT+NSEND=0,10\r\n3333333333
<RX> [W,0]\r\n[S,0]\r\n

10. Disconnect the connection with the third TCP Server

Do below command in order to disconnect current connection.

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n

Example 4. Data communication with more than two devices in Static IP​

1. Set WIZ550SR with Static IP

Set Network IP(192.168.3.101), Subnet Mask(255.255.255.0) and Gateway(192.168.3.1) in WIZ550SR.

<TX> AT+NSET=S,192.168.3.101,255.255.255.0,192.168.3.1\r\n
<RX> [S]\r\n

2. Open a UDP socket
Open a UDP socket with its local port 5000.

<TX> AT+NOPEN=U,5000\r\n
<RX> [S,0]\r\n

3. Get data from the first UDP device

If the first UDP device, which its IP address is 192.168.3.201 and port number is 4001, sent "AAAAAAAAAA"
then WIZ550SR notify to you like below.

<RX> [R,0,10,192.168.3.201,4001]\r\nAAAAAAAAAA\r\n

4. Send data to the first UDP device

Send 10 bytes data "aaaaaaaaaa" to the first UDP device.

<TX> AT+NSEND=0,10,192.168.3.201,4001\r\naaaaaaaaaa
<RX> [W,0]\r\n[S,0]\r\n

5. Get data from the second UDP device

If the second UDP device, which its IP address is 192.168.3.202 and port number is 4002, sent "BBBBBBBBBB"
then WIZ550SR notify to you like below.

<RX> [R,0,10,192.168.3.202,4002]\r\nBBBBBBBBBB\r\n

6. Send data to the second UDP device

Send 10 bytes data "bbbbbbbbbb" to the second UDP device.

<TX> AT+NSEND=0,10,192.168.3.202,4002\r\nbbbbbbbbbb
<RX> [W,0]\r\n[S,0]\r\n

7. Get data from the third UDP device

If the third UDP device, which its IP address is 192.168.3.203 and port number is 4003, sent "CCCCCCCCCC"
then WIZ550SR notify to you like below.

<RX> [R,0,10,192.168.3.203,4003]\r\nCCCCCCCCCC\r\n

8. Send data to the third UDP device

Send 10 bytes data "cccccccccc" to the second UDP device.

<TX> AT+NSEND=0,10,192.168.3.203,4003\r\ncccccccccc
<RX> [W,0]\r\n[S,0]\r\n

9. Close UDP socket

<TX> AT+NCLOSE=0\r\n
<RX> [W,0]\r\n[S,0]\r\n