Mod Bus Implementation...

[cesimkaol]

I dont know have information about modbus implementation on any microcontroller...

I need to know that is UART capable for implementation...Could you please define connections and recommended ICs for me...

 

[FvM]

Review MODBUS over Serial Line Specification and Implementation Guide. Downloadable from modbus.org

 

[paulfjujo]

Hello,

wich mode :
Master or Slave ?
Modbus RTU or Ascii ?
Rs232 linked ?
how many equipment connected together ?
if many,use of Rs422 or Rs485 or Rs232 current loop
or maybe Ethernet with a modbus Lantronix port
wich can be the easyest solution but not tested by myself
you have an example ohf pic master on my web page
and also example for MikroC modbus routines.

don't forget modbus web site.. and some studies to do
before programing

go ahead now !

 

[arbj2]

what about PROFIBUS???

I hear a lot about PROFIBUS, do I have to use their ASIC for this ?? Are ASICs cheaper or a AnyBus communicator device ??

 

[FvM]

There are various previous threads about PROFIBUS, the question is off-topic here.

A short answer though, PROFIBUS ASICs are cheaper of you look at only part costs but don't forget the huge software effort, the advantage possibly pays above some 1000 devices.

 

[cesimkaol]

Hi ,
You are right , ı should gave more information about what I am doing right now...

It is gonna working as slave mod and RTU.More than one equipment will be in system , 4-5 slave and master. Dıstance is more than 20 meters so I have to use RS485.
Could you please give more defination.

Thanks in advance...

Hello,

wich mode :
Master or Slave ?
Modbus RTU or Ascii ?
Rs232 linked ?
how many equipment connected together ?
if many,use of Rs422 or Rs485 or Rs232 current loop
or maybe Ethernet with a modbus Lantronix port
wich can be the easyest solution but not tested by myself
you have an example ohf pic master on my web page
and also example for MikroC modbus routines.

don't forget modbus web site.. and some studies to do
before programing

go ahead now !

 

[paulfjujo]

Hi ,
Dıstance is more than 20 meters so I have to use RS485.
Thanks in advance...

in RS232 current loop , you can reach 100 meter at 9600 bauds..
but it's a "has been " solution..
now, in industrial contexte , we prefere to use Ethernet TCP/IP modbus.
and use for old PLC (as April SMC600) a gate RS232/Ethernet . ex: MOXA
so you can manage modbus like in old RS232 fashion ..

it's why, i told you about Lantronix Modbus to connect all on the same LAN

but in your case, if MAster and Slave are microcontrolers , better way is to use RS485