Here is a fork that seems the most up to date, but I will not say for sure it is the exact fork I used.
https://github.com/angeloc/simplemodbusng On Monday, October 26, 2020, 12:36:13 PM EDT, Rodney Radford <[email protected]> wrote: Please provide a link to the modbus library you use. This is where I found the information I saw about RTU on RS-485 board https://www.arduino.cc/en/ArduinoModbus/ArduinoModbus On Mon, Oct 26, 2020 at 11:11 AM John Vaughters via TriEmbed <[email protected]> wrote: > oh, forgot to mention the Pi 3.3v Tx -> ard Rx is just accepted via threshold > limits and therefore is just a direct connect. > > > > > > > On Monday, October 26, 2020, 11:08:57 AM EDT, John Vaughters via TriEmbed > <[email protected]> wrote: > > > > > > Rodney, > > There are a number of modbus libraries out there, so I'm not sure which one > you are referring to. Yes, when I said UART, I specifically meant TTL. I use > a very simple voltage divider for the ard Tx -> Pi Rx with one resister value > and 3 resistors. I think I have used both 10k and 1k ohms and parallel two > resistors to get half the value and series the third resistor. This gives you > a super simple interface to the arduino that is 5V -> 3.3 Pi. I use the 5V > pin of the Pi to power the 5v pin of the arduino. GND common of course. I use > the simple-modbus Library code and I hesitate to give you a link, because in > doing a quick search, I am not sure which code I am currently using, but the > concept of this library is to use a very minimal set of modbus functions with > holding registers only. This can be used to gang bits into a single register > for binary, if I remember correctly. Thinking from the top of my head, so > check that. I think you will find a couple forks of the original > simple-modbus. Then I pass it onto mbusd to convert it TCP. So the serial is > MODBUS RTU and mbusd converts it to MODBUS TCP. > > What I like about this config and have been using it for a couple years is it > is super reliable. UART being one of the oldest most reliable comms and > MODBUS being one of the oldest most reliable industrial protocols, it makes > for a a very reliable and recoverable from hard reboot combination. However, > there are even more complete modbus libraries that I have used in the past, > but simple-modbus, well..... is simple :) > > John Vaughters > > > > > > > On Monday, October 26, 2020, 10:23:19 AM EDT, Rodney Radford > <[email protected]> wrote: > > > > > > I have not used the modbus Arduino code before, but it does look interesting. > However in reading the description they state it is designed to use with > either their Ethernet shield or the RS485 shield, but I did not see anything > on running it with just a standalone Arduino. If it is possible to just use > the TTL serial port of the Arduino, that would be very nice, indeed. > > _______________________________________________ > Triangle, NC Embedded Computing mailing list > > To post message: [email protected] > List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org > TriEmbed web site: http://TriEmbed.org > To unsubscribe, click link and send a blank message: > mailto:[email protected]?subject=unsubscribe > > > _______________________________________________ > Triangle, NC Embedded Computing mailing list > > To post message: [email protected] > List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org > TriEmbed web site: http://TriEmbed.org > To unsubscribe, click link and send a blank message: > mailto:[email protected]?subject=unsubscribe > > _______________________________________________ Triangle, NC Embedded Computing mailing list To post message: [email protected] List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org TriEmbed web site: http://TriEmbed.org To unsubscribe, click link and send a blank message: mailto:[email protected]?subject=unsubscribe
