WEBENCH® Tools/SN65HVD1782: Derive 2 Rs485 (SN65HVD1782 ) using single enabling pin from mcu

2rs485 signal from it. Can u please help me *


Waiting for ur reply

Thanks

Divyanshu,

I might not understand your problem correctly. Can you drive one SN65HVD1782 with the MCU enable, and drive the other one by the same signal but with an inverter? Please let me know if it works for your application.

Regards,
Hao

hi
Greeting for the day

My application to convert my Ethernet signal to Rs485. So i have a module to convert my signal Ethernet to Uart . The module has 2 uart in it
I am putting RS485 Ic to convert that signal to Differential from Ethernet in both the uart.

Now i am facing problem is that , I have Two uart in that module. For Rs485 we need 3 pins from the controller i.e RX,TX,DE mainly.
UART0 is having these pin clearly RX0,TX0,DE.

I want to ask how can i put my Rs485 on Uart 1 to convert this signal i have TX1,RX1 But not any enabling pin . Can i use same enable pin for both the IC..?
Or should i go for someother way for it.

I cant handle the stack for That module its already build.

Waiting for ur eager response

Kind Regards

Another thought: do you have 3 state output in your UART? If so, you can share the two TX pins to make one active and another one high Z. Unfortunately RS-485 don't support arbitration.

Regards,
Hao

hi

U mean to say hardware active...?
Is there any other way out just like having same enabling the pins ...?
or we can use full duplex and convert that signal two half duplex with that pin..?

There are devices i have seen they use 2 halfduplex to convert the signal to full duplex with that module only..?How that can be possible do u have any idea..?



Thanks

Hi,

After reading your posts more times, I have some questions about the function of your application. 1) Do these two UART get the same Ethernet signal? 2) If so, do you want to split the same signal to two RS-485 signals? I drew a simple block diagram. I'm a little confused why you want to drive one RS-485 by two UART with the same signal.

Regards,

Hao

hi,

This Block diagram shows exactly my problem. Yes it has only one Ethernet port to drive both RS485 Signal.

My module has only one enable port. to enable RS485 so i just want know is there anyother way to drive both at the same time 

Thank ypu