wip_getFile after wip_putFile complete

Legacy Open AT
1

FASTRACK SUPREME 10
OPENAT SDK 7.3
ftp-put example created from the Open AT project wizard, WIP , Version 5.10.2020, 256K, eclipse
After upload the data.txt file, i want to download anther file from the FTP server.
The code in data channel after update all the data is below:

case WIP_CEV_WRITE: {
    int nwrite = wip_write( dst_data, buffer, sizeof( buffer) - offset);
    if( nwrite < 0) { /*error*/ return; }
    offset += nwrite; /* Update the number of bytes sent. */
    if( offset == sizeof( buffer)) { /* All of [buffer] has been sent */
      wip_debug( "Upload finish\n");
      //wip_close( dst_data);   //dst_data   = NULL;
      //wip_close( dst_ftp_cx); dst_ftp_cx = NULL;
     [i][b] dst_data = wip_getFile(dst_ftp_cx, "test-1.txt", evh_data, NULL);
      if(dst_data == NULL)
      {
          wip_debug( "Create download channel fail\r\n"); 
      }
      else
      {
          wip_debug( "Create download channel success\r\n"); 
      }[/b][/i]    }
    break;
  }

Debug messages got from the Uart:
[FTP<=] STOR data.txt
[FTP=>] “150 Opening BINARY mode data connection for data.txt.”
[WIP] new spawned TCPCLIENT 0x180c4b54
Upload finish
ERRLOG ftp.c:187: returned NULL
Create download channel fail
[WIP] closing CHANNEL 0x180c4ad4

If close the data channel by calling wip-close(), before wip_getFile.

if( offset == sizeof( buffer)) { /* All of [buffer] has been sent */
      wip_debug( "Upload finish\n");
      wip_close( dst_data);   dst_data   = NULL;
      //wip_close( dst_ftp_cx); dst_ftp_cx = NULL;
     [i][b] dst_data = wip_getFile(dst_ftp_cx, "test-1.txt", evh_data, NULL);
      if(dst_data == NULL)
      {
          wip_debug( "Create download channel fail\r\n"); 
      }
      else
      {
          wip_debug( "Create download channel success\r\n");

The debug messages are:
[FTP<=] STOR data.txt
[FTP=>] “150 Opening BINARY mode data connection for data.txt.”
[WIP] new spawned TCPCLIENT 0x180c4b54
Upload finish
ERRLOG ftp.c:187: returned NULL
Create download channel fail
[WIP] closing CHANNEL 0x180c4ad4
[WIP] closing TCPCLIENT 0x180c4b54
[WIP] closing WRAPPER 0x180c4a34
[FTP=>] “226 Transfer complete.”

The question is : how to dowload file from server after upload one file? Any sample code? Thanks a lot.

2

I have same problem.
I can’t open write and read channel under one control.
Even if I close first before opening second

ERRLOG ftp.c:187: returned NULL