Differences between SIM300 and SIM340 GSM modules?

[lubchoh]

Hello guys,

I've recently came to this problem after we had to switch to SIM340 using SIM300 successfully for years (just SIM300 was out of stock). Browsing between both of the datasheets they seem to have minor differences (in fact in most of the literature and the shops they are written as equal - SIM300/SIM340) but the code I used for GPRS initialization and communication with SIM300 doesn't work with SIM340.
If somebody had a similar problem and want to share his knowledge please give me a hint. Here is the code and the responses:

SEND COMMAND                           EXPECTED RESPONSE                          ACTUAL RESPONSE
                                                         (as in SIM300)                                  (in SIM340)
AT                                                        OK                                                     OK

AT+CSQ                                                OK                                                     OK

AT+CGATT=1                                        OK                                                     OK

AT+CGDCONT=1,"IP","wap.globul.bg"      OK                                                     OK

AT+CSTT="wap.globul.bg"                     OK                                                     OK

AT+CIICR                                               OK                                                    OK

AT+CIFSR                                      Some IP Address                    223.228.164.238

AT+CIPSTATUS                                     OK                                                      OK

AT+CIPHEAD=1                                      OK                                                      OK

AT+CDNSORIP=1                                    OK                                                      OK

AT+CIPSTART="TCP","www.technosphere.in","80"                 OK                              OK

                                                                              connect Ok                     ERROR: 6

                                                                     STATE: IP STATUS

AT+CIPSEND                                                                      >                         ERROR: 6

Since I couldn't major differences in the datasheets of both modems I'd be grateful if somebody can help me.

Regards,
Lub

 

[chopsuei3]

Good day to you Lub,

I have a similar situation to you - we use the SIM340Z module in our modems, and I have found 2 different revisions among our inventory.

Looking closer, they behave similarly, but I notice from time to time, they fail calls differently - the SIM340 being more prone to errors (e.g. registration errors, rejections, CGREG and CREG responses varying, and AT+COPS not responding correctly).
On the module itself is a version number, which suggests the SIM340 is just a rebadged SIM300 (possibly with newer firmware, etc.).
The 2 versions of our SIM340Z modem are labeled with "SIM300_V6.02" and "SIM300_V7.03" which clearly look to be versions of the SIM300 module.

In my testing, I've found that "V7.03" surprisingly behaves worse, and can incorrectly report it is roaming when it isn't (AT+CGREG and CREG = 2,5). Additionally, other AT commands don't seem to respond correctly, such as AT+COPS, which should output the available networks in the area, but instead, fails to respond within the adequate time period. In fact, we don't even get an OK response.
I've also seen additional characters inserted into the LAC or Cell ID when CGREG and CREG is set to 2, which may cause problems with cell selection. For example, a Cell ID of 5a5 may be missing the first digit which would only display "a5" as the Cell Id, and similar issues to this.

In the past, we've been able to identify very minor, albeit bugs, in various versions of the SIMCOM firmware, like the ones I mention above.
It's possible the versions you have are both early versions and maybe have some bugs that have been fixed since (within the module).

Check your module information using the following commands and reply back -
AT+CGMM
AT+CGMR

For the SIM300_V6.02 module, the responses are as follows -
AT+CGMM
SIMCOM_SIM340

AT+CGMR
Revision:1604B07SIM340M32_SST34HF3284

The firmware version can be found after the first 4 digits, so in this case, we have B07 version of firmware.
You should be able to contact SIMCOM or your distributor to get the firmware updated, although keep in mind the SIM340 is EOL and has been for a while.