For this i want the RS232 on the back from my 19" casing, to avoid ground loops a like the galvanic separation from the RDS-MAX...
![:D](./images/smilies/icon_biggrin.gif)
but it's not 100% separated the transmit from the RDS Max to pin2 from the RS232 has some connection with the internal +5Volts.
Can i use only pin3 and pin5 to send data TO! the RDSmax? it seems the program doesn't need any readback from the RDSMAX (maybe pin2 is only needed for firmware upgrade) if i only can use pin3 and pin5 i have 100% galvanic separation! and i can make a 'special' cable for firmware upgrade...
Other thing are those three extra messages... how can i make them to work? i connected the pins to ground, i tried momentary connections but no luck the normal RDS text keeps scrolling like nothng happend.
Then the TA switch, when do i send TA when the switch is open? or when the switch is closed?
And is there any adjustment procedure? there is a moreturn potentiometer on the PCB, is this for the 4uS delay between RDS data and RDS clock? if so how can i measure if this is OK, some receivers have much RDS erros.
Also for the PLL lock, is there i measuring point where i can see that the PLL is locked to the 19Khz (the LED only dims a bit)
A lot off questions and i hope you can help with this great! product.
Greetings Mark