usb to rs485 full duplex communication

[ertansuluagac]

understood. But I pressed it as a printed circuit. I have to solve this problem. Let's see if I handle it, I will write the problem_: S
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[Ttelmah]

That's just the USB connector.

Are you using your units both ends between two PC's?.
You talk about a PC 4-terminal block. It is details of how this is
physically generated that I want.

The circuit you originally posted was for a PIC and full duplex
RS485 connection to this. This needs something else at the other
end. You talk about 'PIC side' and 'PC side. No such thing. To work
and be seen to talk, you either need two PC's with two of these units, or
one of these with a PC and another unit with RS485, and perhaps an LCD.
At times you talk as if you have a PC RS485 connection. If so, what
is generating this?.
So describe what you are actually doing.

[ertansuluagac]

https://1drv.ms/u/s%21AskLNX_iFag3gfRmuqqSe1dENeQKnw

https://1drv.ms/u/s%21AskLNX_iFag3gfRlYWHvNOB3wbyMsQ

https://1drv.ms/u/s%21AskLNX_iFag3gfRj-H3-Cq1CgfIpcQ

https://1drv.ms/u/s%21AskLNX_iFag3gfRiJefbTnujO1hgxA
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[emaxxenon]

I saw such a scheme.

A --> 1K --> +
B --> 1K --> GND

[ertansuluagac]

I don't think the problem is caused by resistors. The problem is related to max488.
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[PCM programmer]

[ertansuluagac]

okay then I will remove the resistance to which Z and Y are connected on the transmission side. I will remove the resistance to which A and B are connected on the receiving side. Will these solve the problem?
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[ertansuluagac]

I did what he said. The problem still continues.
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[PCM programmer]

[Ttelmah]

Have you got a part number for the USB to TTL module?.
What is the wire you are using?. The termination required depends on this.

[ertansuluagac]

I sent you everything as a picture. I do not understand what you mean. I don't use USB-TTL. What I use is in the pictures. There is nothing else. I still do not understand there is untold. The wire I use is 0.25
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[temtronic]

well I'm confused since you say 'I don't use USB-TTL' but you post pictures and schematics of them....

please post a schematic of exactly what you're using , I want to help, as do others.

I understand English isn't easy, I'm STILL struggling after 66 years !
Thta's why PICTURES are better !!

Jay

[ertansuluagac]

I shared all the pictures. What you call USB-TTL tracks. You'd better give an example. I don't understand what you mean. I sent the circuit diagram and pictures.
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[Ttelmah]

Er. I'm having a really strong nasty feeling.

When I queried earlier, he gave a part number for a standard USB
connector. His circuit instead shows a USB-TTL module. I'm having
string feelings he doesn't actually have a USB-TTL module, but is connecting
the USB signals directly into the MAX1488 driver. No wonder it won't work...

You have to understand that the MAX1488 needs to connect to a TTL
level async serial signal. If you want to drive this off a PC, you need
a USB to TTL adapter module to generate this. USB cannot directly
connect to RS485 without such an interface.

[ertansuluagac]

is this?[url]
https://www.google.com/search?q=usb+ttl+module&bih=657&biw=1366&rlz=1C1SQJL_trTR823TR823&hl=tr&tbm=isch&source=iu&ictx=1&fir=IVOSvlL8OvPa4M%253A%252CLTGsSMC8Oz17-M%252C_&vet=1&usg=AI4_-kRbtoB3-9eCk7LA_8-J8s-xuMdfYg&sa=X&ved=2ahUKEwjk6fPr76noAhVmCWMBHcvVCgUQ9QEwBHoECAoQJA#imgrc=IVOSvlL8OvPa4M:[/url]
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