+IPD,0,xx after 0,CLOSE

[hjani]

Hello everyone!

As the subject states I receive an IPD command after an unexpected tcp connection close on the channel 0 for example. Is it a normal behavior?

+IPD,0,10:#GETSTATE
AT+CIPSEND=0,21

OK
>

Recv 21 bytes

+IPD,4,11:#CRAFTBOT?

SEND OK
AT+CIPSEND=4,19

OK
>

Recv 19 bytes

SEND OK
0,CLOSED

+IPD,0,10:#GETSTATE
AT+CIPSEND=0,21

link is not valid

ERROR
0,CLOSED
0,CONNECT

+IPD,0,10:#GETSTATE
AT+CIPSEND=0,21

OK
>

Recv 21 bytes

SEND OK

[pratik]

That should not be normal.
Can you provide information on the SDK version you are using or the output of AT+GMR command?

Also, please describe your setup if possible. How are your devices connected?
Also, what is the time interval between getting 0, CLOSED and +IPD,0 command? Is it in the order of seconds? Or is it in the milliseconds range?

[hjani]

In our config ESP acts as a server listening on port 80 for TCP connections and also it listens for UDP messages which is used to detect machines. The GETSTATE rate is 1 sec and the UDP broadcast message is sent with 2.4 sec rate.

Here is the complete initialization:

ready
AT+RESTORE


OK

ets Jan 8 2013,rst cause:2, boot mode:(3,0)

load 0x40100000, len 31320, room 16
tail 8
chksum 0x69
load 0x3ffe8000, len 2132, room 0
tail 4
chksum 0x44
load 0x3ffe8860, len 7712, room 4
tail 12
chksum 0x11
csum 0x11
îΓ£ ∞pén∞|ré₧~bbllll`îΓ£εÆpéî≥î l`îΓ£εÆpé∞≥î l`îΓ£εÆpéÄ≥î ll`rlÄÉnî₧bbî|îbbÄÆîÄé£Γ£b∞p~ÆnnnΓé£ îbÆénllîÇlîÄ l∞Ä∞lÄαîÉl`Çnⁿî₧bbllÄÆbî₧bblîbrlrl
ready
AT+CWMODE_CUR=3


OK
AT+CWJAP_CUR="PETYA2","wifipassword"

WIFI CONNECTED
WIFI GOT IP

OK
AT+CIFSR

+CIFSR:APIP,"192.168.4.1"
+CIFSR:APMAC,"5e:cf:7f:c0:b5:73"
+CIFSR:STAIP,"192.168.1.21"
+CIFSR:STAMAC,"5c:cf:7f:c0:b5:73"

OK
AT+CWSAP_CUR="CraftBot_RC0A80115","devicepassword",1,4


OK
AT+CIPMUX=1


OK
AT+CIPSERVER=1,80


OK
ATE1


OK
AT+GMR

AT version:1.3.0.0(Jul 14 2016 18:54:01)
SDK version:2.0.0(656edbf)
compile time:Jul 19 2016 18:43:55
OK
AT+CIPSTART=4,"UDP","0",0,80,2

4,CONNECT

OK

[pratik]

I tried the same but never got the problem that you are getting.
Are you using an old AT command firmware? I tried with firmware based on the nonOS SDK v.2.0.0