# Enabling RTS / CTS Flow Control

{% hint style="info" %}
The flow control of the Microhard Telemetry Radio module is turned off by default, and can be turned on or off by the following methods.
{% endhint %}

### Enable CTS/RTS

1）Connect a USB cable from the PC USB port to the USB TYPE-C of the module.

2 ) Launch a terminal communications program (e.g. HyperTerminal) and configure for 9600 bps, 8 data bits, No parity, 1 stop bit (8N1), no flow control.

3 ) press and hold the CONFIG button and apply power to the module.

4 ) release the CONFIG button

5 ) On power up the terminal session window should show “NO CARRIER OK” as seen below:

<figure><img src="/files/C7V0GQtwZbKpYLyzhJjF" alt=""><figcaption></figcaption></figure>

6 ) the P900 is now in command mode, and AT commands can be used to configure or query the settings.

7 ) Type in AT\&K3 and press Enter will enable CTS/RTS handshaking.

8 )  Type in AT\&W and press Enter to save the configuration to the NVRAM  of the module. Then, the configuration will not be lost after the power off.

&#x20;

### Confirm Configuration

9 ) Power off and redo step1\~5.

10 ) Type in AT\&V and press Enter will display the current configuration as seen below: (Handshaking & K3 means CTS and RTS are already enabled.)

<figure><img src="/files/TUwuMIDCcporRlGRftZi" alt=""><figcaption></figcaption></figure>

### Disable CTS/RTS

11 ) redo step1\~5.

12 ) Type in AT\&K0 and press Enter will disable CTS/RTS handshaking.

13\)  Type in AT\&W and press Enter to save the configuration to the NVRAM  of the module.

### Confirm Configuration

14 ) Power off and redo step1\~5.

15 ) Type in AT\&V and press Enter will display the current configuration as seen below: (Handshaking & K0 means CTS and RTS are disabled.)<br>

<figure><img src="/files/4DgSBAOM4b6T7G17pBnK" alt=""><figcaption></figcaption></figure>


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