Hi Zigg,
Thanks for the answer. I've moved the GND to PIN 7 on the RS232 plug for the printer. It should be SIG GND but no improvement.
Between the printers TX and SIG GND there is 9.8V and 0V between RX and SIGGND. So I asume that this is not a TTL port and the wireing is not crossed correct. Shouldn't a 25pin serial port that the printer have , always be a rs232?
I'm still getting garbled results. I've tried to move to pin 11 and 12 but no result either.