Printing to a new unknown Panel Printer

[Shantanu24]

Hi.
I have just found one panel printer in one of the scrapped parking entry systems.
the pins on the printer control board are the following:
24V input
GND
GND
RXD
TXD

Now i have a USB to TTL converter. I have attached the image as an attachment

Connections i have made as the following

Printer USB-to-TTL Raspberry Pi
GND------------------GND-------------USB end of the raspberry pi
RXD-------------------TXD


I have made all the settings as mentioned in the article
http://www.instructables.com/id/Read-an ... pberry-Pi/

When i run the code mentioned in the above link, the light on the ttl-to-usb converter TXD pin blinks. Which i suppose indicates that the data is being sent. But the printer does nothing.

What could be the issue?