Sim900 FTP commands problem

[ngc5194]

Hello,
Im working with sim900 module and im trying to send data to FTP server using simcom FTP commands. how much time i should wait for commands as AT+FTPGET=1 to respond with +FTPGET:1,1?

 

[ngc5194]

Sorry to bother you again but if someone knows when error 77 occur using +FTPGET. In sim900 at commands manual for this error is written "operate error", but im not shure what that means?

 

[profiblaster]

I have the same problem. Any soluton ?

 

[ngc5194]

unfortunately, i haven't been able to find some valid solution for this problem..
i managed to make my program work by giving large time delay between command and reading the answer.. as you can guess this solution is rather slow.. also, problem is because i have to send few files to ftp server, and for each file sim900 is connecting to server ( password, user name, etc ), and its large waste of time... so for 4 files ( 1 download (30B) , 4 upload (together not more then 200B)) it takes more then 1 and half minute ( and sometimes even 3 or 4).. It could be much faster if these timeouts between commands and answer are shorter, but then the code is very much unreliable. Maybe the solution is not to use FTP commands when you are working with multiple files ( because the connection is established for each file.. ), but it seems complicated do make normal TCP connection ( it takes two different connection, one for data, and other for commands .. )

 

[edwintas]

response time from SIM900 seems to be affected much by the network. when i upload 500b in the Philippines to an FTP server, it took more than 2mins before i get a reply OK from the module. but when i do it here in Singapore, 500b upload takes only around 15sec.

unfortunately, i haven't been able to find some valid solution for this problem..
i have to send few files to ftp server, and for each file sim900 is connecting to server ( password, user name, etc ), and its large waste of time.

i don't encounter this when i do multiple file upload. after i finish uploading with 1 file, i just set the new file name, and proceed file upload after that.

 

[ngc5194]

Yes, thats the main problem, response is so much affected by the network... Thats way i thought it s slow due to multiply connecting to server, but i was wrong. In my project, i have to have specific timeout for sim900 to respond to command ( network dependable ), but sometimes it happens that sim900 does not respond after that amount of time, and after that i have problem in executing at commands ( it s like sim900 is waiting for response, and cant do anything else ). Maybe, you have some solution? Im rather new to all this, so sorry if this is some basic stuff...

 

[edwintas]

the problem lies on network error. if you dont have good signal, you will get disconnected without notifications. that will cause a lot of problems. sorry nut i dont have any work around for that.

 

[syeda amna]

I am facing the same problem. Is there any solution for this?

 

[ngc5194]

I am facing the same problem. Is there any solution for this?

Unfortunately, I`ve been searching for solution for long time, but without success. Answer is network dependent and you cannot know how much u will have to wait. Also, there are some other problems i found using sim900 ftp commands.. So, my best advice is to make ur own ftp client/server using at commands for creating ppp connection.

 

[fsperdy]

I am facing this problem too. Is there any news?