Commonly used RS232 based protocols

Hi,

I am supposed to integrate a motion control system into the factory shop floor. The motion control system uses a RS 232 with a proprietary protocol consisting of the following structure.

<command (fixed size=1 byte)><fixed data size=15 bytes>

I need to know what standard RS 232 based protocols are used commonly in the industry ??

I know some like MODBUS RTU, or even PROFIBUS could be counted as valid options. But are there any other protocols, that I am missing.

I will be looking in the internet, but in the meantime if anyone could give me their valuable opinion it would be great.

thanks
a

At the end of the day you need to know these when you are specifying projects.
there are many what is your requirements.
(loaded Question I think)
If this is, as I suspect, A school project question.
then kindly state it - we will give you the usual answers.

For the record RS232 is not comparable to Profibus
Profibus is is a two wire shielded system but it is a multidrop system

Modbus - ok

If this is, as I suspect, A school project question.
then kindly state it - we will give you the usual answers.

Click to expand...

No its not a school project. Its an actual project that could be implemented in the near future, in the meantime I am gathering information from the people who actually work with communication protocols and such stuff (ie: members in this forum)

Basically what I need is a RS 232 based communication system that can be easily implemented in a PLC by the end user.

I thought of a packet structure like this. The packet structure below would be generated by a PLC

<command (1 Byte)><data payload(16 bytes)><Checksum (ADD type)>

Command: action to be done by the motion control system
Data Payload: parameters to be supplied to the machine control system
Checksum: ADD type, simply sums up the entire packet.

Can a PLC be programmed for generating the above packet ??

the response by the slave device would be the command identifer, followed by response data (status etc.) and the checksum data.

Do you think this

For the record RS232 is not comparable to Profibus

Click to expand...

Yes I realise that but I was referring to the profibus packet itself, I thought maybe this could be modified for use in RS 232 (point to point).

I did find some others like SLIP (serial line interface protocol), but this seems more suited for TCP/IP based networking. X-MODEM looked OK, but I am not sure its used these days.

It seems I have to make my own protocol...

I realise the question is very vague and general. But at this stage I do not have much data.

thanks
a

these days we are heading towards E/net and slight variations of that.
Twincat.

ASLO other mfg's DH+ , Canopenbus , devicenet

there is still (RS484 and RS422 - Multidrop serial

And HART Protocol

Most PLC's have Either RS232 of 422/485 available
and the programming protocol to comunicate
but
what to and from

If I was setting u a system today i would be trying for e/net as much as possible.
all depends on system constraints

If you want to look at motion check out EtherCat - many products available - small packets - fast.
http://www.ethercat.org/default.htm
Serial, particularly RS232, is painfully slow. RS485 is not to bad but RS422 is probably the best of the straight serial communication because it is duplex at least - still painfully slow.

there you go I knew I would not get all of them
I thought Twincat and Ethercat were the same
Dosent matter if not at the moment I dont use them

I'm a process guy whose "motion control" experience is limited to valve or damper actuation, so I gotta ask or controlling conveyor speed.

Is serial data motion control all talk, no listen?

No serial data feedback of any sort?

The controller is a barking drill sargent? "Do this, go there, do that!"

Any or all feedback, like a limit position, is discrete or analog?

iant said:

And HART Protocol

Click to expand...

HART is primarily used to configure field instruments. It is slow (1200 baud) and is superimposed on a 4-20mA analog signal (although it can be stripped off with a Bell modem, it is not inherently serial). The HART Foundation no longer has an 'open' spec, it now requires paid membership for access to the spec.

HART would have little, if any, applicability in motion control.

To many communication protocol i also confuses

Thanks DanW but it is still s form of comunication that was what i meant