In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time (in contrast to a parallel port). Throughout most of the history of personal computers, data was transferred through serial ports connected the computer to devices such as terminals and various peripherals.
Connecting to a device (modem, router, switch…) via the serial port. This is useful if you don’t have remote access (or got kicked out) or a KVM on your device.
- The device with a Serial Port 9 PIN
- A USB Serial adapter for your Mac
- A Null Modem DB9 cable
- Zterm: Terminal emulation program
First you need to install the driver of your USB Serial adapter on your mac.
Please refer to the manufactured website.
For this post I used two types of adapters: Trendnet TU-S9 (v2.0R) and STLab U-224
Checking if your USB to Serial adapter driver is installed correctly
Don’t forget to reboot after installing the driver!
After pluging your adapter into the laptop:
- Open the “System Information” and go to the “System Report”
- On the left list go to “USB”
- On the right, you should see the “USB Device Tree”
- Under that list you should have “USB-Serial Controller D”
- In “Settings” > “Terminal Settings”:
- Make sure these are checked: “No Extended Chars” , “VT100 Keypad” – “VT100”
- In “Settings” > “Modem preferences” :
- Serial Port: “usbserial”
- In “Setings” > “Connection”: (adapt this to fit your device serial port configuration)
- Data Rate: 9600
- Data Bits: 8
- Parity: None
- Stop Bits: 1
Connect the device and your laptop with a Null Modem cable…
Voila! Zterm should now show the output of your device, otherwise recheck your Zterm configuration.