HTTP request

PLCnext Engineer
1

Anybody done a successfull HTTP request with tcp_socket and tcp_send? Tried this: TCP_SOCKET1(

ACTIVATE := activate,
IS_SRV := false,
BIND_IP := ‘’,
BIND_PORT := 0,
DEST_IP := ip,
DEST_PORT := port,
HANDLE => handle,
ACTIVE => active,
BUSY => busy,
ERROR => error,
STATUS => status,
USED_PORT => usedPort
);

//size := SIZEOF(sendData);

TCP_SEND1(
REQ := req,
HANDLE := handle,
DATA_CNT := size,
DONE => sendDone,
BUSY => sendBusy,
ERROR => sendError,
STATUS => sendStatus,
DATA := sendData
); Sending data to a tcp input in node-red. The data i am sending is: GET /test HTTP/1.1\ \ \ \ When setting the data_cnt=26 i’m getting the following on the other end: PGET /test HTTP/1.1\ \ So i have to add four bytes to the count to get the complete string, data_cnt=30 Then i get this: PGET /test HTTP/1.1\ \ \ \ Where is the P coming from?

2

Hello, I am guessing that you are sending an IEC STRING as your data, which includes two header bytes representing the maximum and actual string lengths. The solution is to send the data as a byte array that does not include the two header bytes. - Martin.

3

You’re right, thanx :slight_smile: -Jørgen