Question about CD emulator schematic

[DdJ]

Hi,

Why don't you use the PCA82C250 RxD pin instead of the LM339?

Thanks in advance for answering,

Kind regards,
Dave

[Vitat]

Why don't you use the PCA82C250 RxD pin instead of the LM339?

PCA82C250 - is a CAN bus driver IC. CANbus and IP-Bus signals are little different. Internal comparator in PCA82C250 have another hysteresis and not compatible with IP-Bus protocol.
IP-Bus comparator can see output from CANbus driver. But CANbus comparator can not see output from IP-Bus driver.
I using simple comparator and adapt hysteresis with 10k and 1M resistors for IP-Bus line.

[Anonymous]

Why don't you use the PCA82C250 RxD pin instead of the LM339?

PCA82C250 - is a CAN bus driver IC. CANbus and IP-Bus signals are little different. Internal comparator in PCA82C250 have another hysteresis and not compatible with IP-Bus protocol.
IP-Bus comparator can see output from CANbus driver. But CANbus comparator can not see output from IP-Bus driver.
I using simple comparator and adapt hysteresis with 10k and 1M resistors for IP-Bus line.

not compatible with IP-Bus protocol and IE-bus protocol  ?

[Vitat]

What is IE-Bus?

[Anonymous]

IE BUS is about the car controlЎЇs protocol of the NEC, these kinds of chips have uPD72042b and uPD6708, you can find them in  www.necel.com. I have used upd6708 and Atmega8 to get the connection between HONDA radio (IE-BUS) and ALPine CD changer (M-BUS), It was   succeed .Now I am making the connection between TOYOTA radio (IP-BUS) and CD changer (S-BUS) which made in Korea. Could you please offer me the protocol and the date of IP-BUS? If I get your help I will offer the message which you interest.