Hi Jarl, As I already write PRS10 is configured as serial communication. With oscilloscope I can see serial signals, but when enter this signal in computer with TTL level USB2serial converter all information is repeatable character unknown for me and not as described in manual. For test i change baud rate, number of stop bits, number of bits without success. Also trace signal to U302 MC68HC11 pin 20 and 21 and both TX and RX are the same as on J100 (external connector) - time/period and amplitude has TTL levels. For me looks like internal ROM has incorrect bits or processor is not in normal state and response from serial port coming from different subroutine. I expect hints how to check processor state. Or how to push processor in state where will have normal serial communication.
Best regards Philip > On 4.03.2016 г., at 9:35, Jarl Risum <jarl.ri...@gmail.com> wrote: > > OK, Philip > > If you have confirmed with a Oscilloscope that no RS-232 communication is > present on the TXD output pin, I sugggest you check the status of R247/R248 > and R353/R354 - see the manuals chapter on "PRS 10 Applications" (page 20), > description of pin 4 and pin 7. > > Good luck > > Jarl > > 2016-03-03 20:08 GMT+01:00 Philip Zahariev <philip_zahar...@yahoo.com>: >> Hi Jarl, >> >> >> >> Of course I use TTL level USB serial converter. Unfortunately, as I write no >> communication, or at least not what I expect. >> >> >> >> Best regards >> >> Philip >> >> >> >> From: Jarl Risum [mailto:jarl.ri...@gmail.com] >> Sent: Wednesday, March 2, 2016 11:49 PM >> To: philip.zahar...@yahoo.com; philip_zahar...@yahoo.com >> Subject: PRS 10 and serial port communication >> >> >> >> Philip, >> >> The outgoing RS-232 port from PRS 10 is a TTL inverter with an approx. 1 >> kohm series resistor. >> >> See diagram of the microcontroller board, upper right corner. >> >> For this reason you may have problems reading the outgoing RS-232 messages >> with a standard RS-232 PC input. But you may see the transmission taking >> place with a oscilloscope. >> >> I have had the same problem with my PRS 10 and solved it with a simple 2 >> transistor non-inverting amplifier fed from a +12V source. >> >> If interested, I can send you the diagram. >> >> Cheers from >> >> OZ9MO / Jarl >> > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
