Hi,

I have few doubts about Modbus:

1. Can Modbus create data groups/classes?

2. Are the data types fixed, or can vendors add specific data types?

3. Does it support Object oriented modelling?

4. Is data model independent of services?

5. Are services independent of communication networks?

6. Am I right in this: Modbus reads single values but can write many values at the same time?

7. What about spontaneous transmission?

Thank you in advance for answering any or all of the questions

 

> 1. Can Modbus create data groups/classes?
Sometimes yes.

> 2. Are the data types fixed, or can vendors add specific data types?
Yes.

> 3. Does it support Object oriented modelling?
Some do.

> 4. Is data model independent of services?
No.

> 5. Are services independent of communication networks?
Yes.

> 6. Am I right in this: Modbus reads single values but can write many values
> at the same time?
Yes, but not in all implementations.

> 7. What about spontaneous transmission?
Can be done, if sometimes called "Report be exception?".

For details see www.modbus.org