MAX232N Not working with Thermal Printer

Nilesh Kulkarni2

Other Parts Discussed in Thread: MAX232

Hello All,

One of our customer is using MAX232N for 2 applications mentioned below :

To transmit and receive data from computer via UART.
To operate Thermal Printer.

They are able to transmit and receive the data from Hyper Terminal. When they connect same board with Thermal Printer then it is not sending or receiving any data.

Competition parts are from ST and MAXIM.

Kindly let us know what should be the issue in the same.

over 10 years ago

0 Ron Michallick over 10 years ago

TI__Guru**** 164726 points

Nilesh,

Can the computer communicate with the printer (not using the MAX232 application)?

There are many things that could be the cause.
Baud rate or parity bits setting is incorrect.
The printer many use more handshaking lines that are not looped back correctly.

Did the ST and MAXIM device work?

Lastly, check the TIN, TOUT, RIN, and ROUT pins on MAX232 to see if the outputs match the input signals (inverted)

0 Nilesh Kulkarni2 over 10 years ago in reply to Ron Michallick

Expert 1120 points

Hello Ron Michallick,

Thanks for your valuable response.

Customer is using only TX and GND pin to connect to printer. No acknowledge is taken back from printer.

Baud rate and parity bits are as per standards. ST and MAXIM are working on same base board,

Above are the sch and Layout for the same.

Kindly advice on the same. Awaiting for your valuable response.

0 Nilesh Kulkarni2 over 10 years ago in reply to Nilesh Kulkarni2

Expert 1120 points

Hello,

I missed out to attach Schematic. Kindly do the needful

0 Ron Michallick over 10 years ago in reply to Nilesh Kulkarni2

TI__Guru**** 164726 points

Nilesh,

The schematic looks good. Do you have access to an oscilloscope to check wave forms at RS232 port pins?
If not use a digital multi-meter to reads voltages at pins 2, 6, 7, 10, 12, 13.

Interface

Interface forum

MAX232N Not working with Thermal Printer