Search found 12 matches

by v.rajaji
Wed Oct 23, 2019 2:00 pm
Forum: Getting Started
Topic: Learn to use 16F628A on ADC, EB005 display control an output
Replies: 22
Views: 21816

Re: Learn to use 16F628A on ADC, EB005 display control an output

Hi Abhijit
Have you had success with RTD?
by v.rajaji
Mon Oct 14, 2019 9:46 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijit

Can you please share your RS485 breakout board schematic or photo for my reference. I am uploading a circuit is it same as yours.

regards,
Raja
by v.rajaji
Thu Oct 10, 2019 2:03 pm
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijit

Finally it worked out for me, the baud rate issue is due to chip configuration settings. By changing CPU system clock select to OSC/1 and OSC select to Divided by 5 (20MHz input). Now I will look into remaining programming stuff.
Thanks for your support.

Regards,
Raja
by v.rajaji
Thu Oct 10, 2019 1:16 pm
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijit Now I found it working with same hardware and same sample program which I uploaded. All it was happened by changing the Baud rate in master device. In flowcode program the Baud rate is 9600 which is not at all communicating with the master device, I changed baud rate to 2400 in the master...
by v.rajaji
Thu Oct 10, 2019 8:55 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijit

Thanks for help. I tried revised program but no luck from my end, my RS485 board receiving data from the PC but no response from PIC. When you have time please check it with your hardware and let me know.

Regards,
Raja
by v.rajaji
Thu Oct 10, 2019 7:40 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi
Example Modbus slave programs are with Read/Write coils only, anybody can share a working Modbus slave program with holding registers.

Regards,
Raja
by v.rajaji
Wed Oct 09, 2019 2:24 pm
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijit

I tried the settings as per yours but no luck. Please check if my coding is correct or not.

Regards,
Raja
by v.rajaji
Wed Oct 09, 2019 12:37 pm
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Abhijith

Thanks for help. can you please check my program to confirm whether I am making any mistake. I need to read/write holding registers rather than coils.
by v.rajaji
Wed Oct 09, 2019 5:23 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi Why I am wondering the same hardware is working normal with Modbus Master component, I can communicate with a 3rd party temperature controller without any hassles. Master is working good even with in house made RS485 board (with 74HC04 and SN75176 for automatic read/write control) by selecting RS...
by v.rajaji
Tue Oct 08, 2019 12:08 pm
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi I tried the Modbus slave component which is working well in simulation, perfectly communicating with my application. But it is not working with real hardware, I used PIC18F2550 with 20MHz crystal and tried two types of readymade RS485 boards as in attached images. When I tried Modbus master with ...
by v.rajaji
Wed Sep 25, 2019 8:49 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Thanks
I will try to download trial version and try it.
Regards,
Raja
by v.rajaji
Tue Sep 24, 2019 8:25 am
Forum: General Programming
Topic: Modbus slave RS485
Replies: 18
Views: 8553

Re: Modbus slave RS485

Hi
I am new to this forum, I don't know how to post a question in this forum. Anybody please advise me which PIC and RS485 hardware is successfully working with Modbus RTU Slave component.