How to communicate with printer from ruby language?

I want to communicate with printer by using ruby language. i am using
socket programming to communicate with printer. my printer ip is
“192.168.24.687” and port number is “20000”.

Below is the code that i am using to communicate with printer

require ‘socket’
sock = TCPSocket.new(‘192.168.24.687’, 20000)
sock.write ‘MARK START’
sock.close

In the above code i am sending “MARK START” command to the printer which
will turn printer ON , but it’s not working. with above code i am able
to established connection with remote server but not able to send “MARK
START” command.

But the same is working with putty. with putty i am using connection
type as “raw” and connecting to the printer.After connection is
successful i can send command “MARK START” to putty and able to turn on
printer.

I want to know why my code is not able to send “MARK START” command to
printer??

Thanks, Sanjay Salunkhe