What kind of protocol do you prefer?

[luca_l]

I ' m looking for a 'Tutorial by Example'  for Modbus!

  or any suggestion are  welcome! 

Many Thanks in advance 

Luca

[lrom]

Hi, I use I2C prtocol.Its fast and requires only 2 pins, and in future you can connect more devices.Configure one pic in master mode and other one in slave mode.

Most PIC's has it as a hardware peripherial.

[narc60]

luca_l,

After reading your post, I looked in the C:\Program Files\PICC\Drivers folder and Modbus.c is indeed included. I should have tried to write a program first. I was trying to gather as much info as possible as I have a project in mind that's why I was searching the CCS forum. Thanks for sharing the info.

[luca_l]

            Dear  Narc60

We are going to  the    same direction,
if you like we can  share our first steps on modbus world ! 
 
cheer
Luca

[tenir]

I use cab bus. its works perfect in noisy environment. it also works good with ccs can driver

[xirix]

Can you suggest a serial bus with followings:
 - master + n slaves
 - large nr. of slaves (~128)
 - master to slaves up to 100-200m
 - power over net (slaves powered by bus; aprox 1mA/slave)
 - small speed (10-50kbps)
 - error checking for noisy environment
 - easy debug in case of failure

Thanks

[vsmGuy]

What about SMBus ?

[xirix]

SMBus is slow speed serial bus derived from i2c. I don't think is usefull for long distances.

[crastoverkill]

Hello, i've coded an PID temperature controller, with some codes i've learned on books, and i've some dificulties to tunning it. system error becomes greater more and more. has one technik in especial for tuning PID for temperature controls? (sorry by my poor english)

[dreamwithin]

I use rs232 for short distance, it is simple but not reliable, I still prefer CAN bus. If you use CCS C ,CAN will be the best and simple way to do communications.

[lillbear]

Hi check S.N.A.P - Scaleable Node Address Protocol -> http://www.hth.com/snap/

S.N.A.P is an free and open network protocol. The protocol was primary developed for PLM-24 based
home automation and control systems but it is a generic protocol and not limited to this. S.N.A.P can be
used in any type of applications where an easy to learn and light weighted network protocol is needed.
Features.
   
   - Easy to learn, use and implement.
   - Free and open network protocol.
   - Free development tools available.
   - Scaleable binary protocol with small overhead.
   - Requires minimal MCU resources to implement.
   - Up to 16.7 million node addresses.
   - Up to 24 protocol specific flags.
   - Optional ACK/NAK request.
   - Optional command mode.
   - 8 different error detecting methods (Checksum, CRC, FEC etc.).
   - Can be used in master/slave and/or peer-to-peer.
   - Supports broadcast messages.
   - Media independent (power line, RF, TP, IR etc.).
   - Works with simplex, half-, full- duplex links.
   - Header is scaleable from 3-12 bytes.
   - User specified number of preamble bytes (0-n).
   - Works with synchronous and asynchronous communication.
   - Works with our free PLM-24 < > TCP/IP Gateway software.

yours

[alichan]

You should take in consideration:

Max speed required.
Ammount of data to be transmited
Max length of wires (distance between MCUs)

These are the main issues to be taken in consideration, of course there're others.
Just can use custom protocols, parallel communication (ppl), rs232, rs482, spi, i2c, field protocols (modbus, iec)... tcp/ip  (why not? it only depends on your needs).

Hard question to be answered with so less information.

Always try the simpliest protocol that solves your needs.