What is DB9 null modem?

Null modem cables are serial cables that use an alternative pinout for different functionality. A standard DB9 AT cable pinout (non-null modem) Originally, all serial cables were AT cables and could not connect two devices (such as two computers) directly. They required a modem or similar equipment as a go-between.

What is null modem why it is required draw and explain its pin connection?

With a null modem connection the transmit and receive lines are crosslinked. Depending on the purpose, sometimes also one or more handshake lines are crosslinked. Several wiring layouts are in use because the null modem connection is not covered by the RS-232 standard.

What is a straight-through RS-232 cable?

A straight-through serial cable is the most common type of serial cable, used to connect a Data Terminal Equipment (DTE) device (for example, a computer) to a Data Communications Equipment (DCE) device (for example, a modem).

How do I check db9 connector?

To monitor your serial port activity, use these simple steps:

1. Download and install Serial Port Tester.
2. From the main menu select “Session > New session”.
3. The “New monitoring session” window should now be displayed.
4. Select “Start monitoring now” if you want to immediately start monitoring the ports.

How do I create a serial port?

To configure the Serial Port for your device, on your computer go to Control Panel – Device Manager, select “High-Speed USB Serial Port (Com X)”, right click and select Properties. Click the Features tab. This tab is used to change the COM port number and configure the port.