# WP7702 USSD support

**URL:** <https://forum.sierrawireless.com/t/wp7702-ussd-support/15557>\
**Category:** IoT Modules\
**Created:** [March 4, 2019, 1:01pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557 "2019-03-04T13:01:14Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![brucej72](https://avatars.discourse-cdn.com/v4/letter/b/ecc23a/32.png) [@brucej72](https://forum.sierrawireless.com/u/brucej72)\
**Post date:** [March 4, 2019, 1:01pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/1 "2019-03-04T13:01:14Z")

</div>

Hi there -  
I’m using a WP7702 module, and am trying to send a USSD message with the command:  
at+cusd=1,"#468_hello#"  
I have configured the module using at!selrat to auto, and am successfully connected to a network where this is supported on other modules from other vendors.  
When I enter at+cusd=1,"#468_hello#" I immediately get:  
at+cusd=1,"#468\*hello#"  
ERROR  
Any ideas?

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<div class="post-metadata">

**Author:** ![mlw](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/mlw/32/3706_2.png) [@mlw](https://forum.sierrawireless.com/u/mlw)\
**Post date:** [March 4, 2019, 2:59pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/2 "2019-03-04T14:59:17Z")

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@brucej72,

Just to clarify the unit is attached to 2G and not an LPWA network (NB1/M1)? It will notwork on LPWA.

Regards

Matt

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<div class="post-metadata">

**Author:** ![brucej72](https://avatars.discourse-cdn.com/v4/letter/b/ecc23a/32.png) [@brucej72](https://forum.sierrawireless.com/u/brucej72)\
**Post date:** [March 4, 2019, 3:10pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/3 "2019-03-04T15:10:49Z")

</div>

Correct, it’s on O2 on 2G. I can force the network to 2G as well via at!selrat and the same thing happens.

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<div class="post-metadata">

**Author:** ![mlw](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/mlw/32/3706_2.png) [@mlw](https://forum.sierrawireless.com/u/mlw)\
**Post date:** [March 4, 2019, 4:01pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/4 "2019-03-04T16:01:33Z")

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@brucej72,

I am having a few power issues when connecting to 2G at the moment i.e. my PC does not provide enough power but it does for LTE/UMTS.

I have tested it on a WP7607 (the WP76xx has the same code base as the WP77xx) against VF when attached to LTE and it works successfully meaning CUSD is implemented and successfully handling the USSD traffic, note the \*#100# string is specific to Vodafone.

As a result I suspect that the string you are sending (#468\*hello#) is incorrect, where did you get it from?

```
at+cops?
+cops: 0,0,"vodafone UK",7
OK
at+cusd=1,"*#100#"
OK
+CUSD: 0,"0737921432",0

```

Might want to send the following

```
at+cmee=1
at+cusd=4,"#468*hello#"

```

Regards

Matt

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<div class="post-metadata">

**Author:** ![brucej72](https://avatars.discourse-cdn.com/v4/letter/b/ecc23a/32.png) [@brucej72](https://forum.sierrawireless.com/u/brucej72)\
**Post date:** [March 4, 2019, 4:19pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/5 "2019-03-04T16:19:18Z")

</div>

It doesn’t matter what the string is. I started with the string:

AT+CUSD=1,"#468\*KOdtAYgEAQAAAQYaGgQEAQAKODlZMjlVUkpORjdaRTNPMUdYQlA=#"

…which we use as a test for modems. It works fine on Telit/uBlox/SIMCOM/Quectel for example, but obviously only with our SIM cards (and therefore on the networks we roam onto, which includes VF, O2, EE, TMO in the UK).

Again, that string just returns ERROR. For example on another vendor modem, I would expect:

-\> AT+CUSD=1,"#468\*KOdtAYgEAQAAAQYaGgQEAQAKODlZMjlVUkpORjdaRTNPMUdYQlA=#"  
\<- OK  
\<- +CUSD: 2,“KLh6AQcHQUNLAOdtAA==”  
\<- +CUSD: 1,“KAgJAQYDAwUA”

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<div class="post-metadata">

**Author:** ![mlw](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/mlw/32/3706_2.png) [@mlw](https://forum.sierrawireless.com/u/mlw)\
**Post date:** [March 4, 2019, 6:38pm UTC](https://forum.sierrawireless.com/t/wp7702-ussd-support/15557/6 "2019-03-04T18:38:01Z")

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@brucej72,

Can you send the following to the unit.

```
ati
at!gstatus?
at+cops?
at+cpin?
at+cimi

```

Also when it returns ERROR does it come back immediately or take a few seconds?

I have tried it on a 3 SIM and it takes a few seconds to come back so it is clearly interacting with the network successfully.

```
at+cusd=1,"#468hello#"
OK

+CME ERROR: retry operation

```

Regards

Matt