# MDB Connection Best Practice

Here is the debug steps that you might want use an serial connection from your Point of Sale machine or Vending Machine or PC.

{% stepper %}
{% step %}

### Install Payment Apps

Option 1: Install Payment Apps, apps can be installed through ADB, or push by TMS.

{% embed url="<https://ftp.wizarpos.com/payment/OPC_V1.7.0-global-release.apk>" %}

{% embed url="<https://ftp.wizarpos.com/payment/PayWizard_Demo_V2.0.0_2508081.apk>" %}

Option 2: Our tech support team also can help you to download these apk to your terminal.
{% endstep %}

{% step %}

### Set Protocal Type to MDB or TMS Push Para to terminal

Option 1: Set terminal connection protocal type to **MDB** in Payment app, refer to PaymentInterfaceAppUserGuide.pdf

{% file src="<https://2631785516-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FY7FuzH91SaNfvhwFA9Ic%2Fuploads%2FnkmPX31oU8SowcD1VXUz%2FPaymentInterfaceAppUserGuide.pdf?alt=media&token=04fa0569-9838-41d0-94c2-fdd364e7729b>" %}

Option 2: Our tech support team also can help you to push parameter to your terminal to modify this settings.
{% endstep %}

{% step %}

### Connect Payment Terminal to MDB Simulator+PC/MDB Device

Example:

<div align="left"><figure><img src="https://2631785516-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FY7FuzH91SaNfvhwFA9Ic%2Fuploads%2FdXxjpae9Zml0eDTa2ZOb%2Fimage.png?alt=media&#x26;token=a6e0afdb-a46f-487b-9a69-378b0ee517e3" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}

### Start Debugging follow MDB protocol

{% embed url="<https://ftp.wizarpos.com/advanceSDK/MDB_Version_4-3.pdf>" %}
{% endstep %}
{% endstepper %}

## **Need more details? Click the link below.**

{% embed url="<https://smartpossdk.gitbook.io/cloudpossdk/cloudpos-sdk/mdb-communication-protocal>" %}