I have a device with modbus rtu RS232.
Can I simply use an RS232 to 485 converter, and connect onto the RS485 multidrop network along with the other modbus rtu devices ?

 

Yes, sure.

 

Simple answer Yes. Things you must check. You must be able to set the modbus address so that all on the network are unique. Modbus only allows 1 master and numerous slaves on a network. Also I would suggest using an industrial 232-485 converter as I have seen problems with reliability and setup of cheap commercial grade converters. The one I personally suggest is from Phoenix Contact.

 

You can use the converter but be sure it is compatible with the other devices. Find out if they use send control or data activation modes. B and B electronics makes a good device that we use as well for conversion. It is the 4WSD9R. RobustData.com also makes some very good units. They also have good information on their website about the application of RS485.

 

You can get moxa (RS 232 converter to RS 485)

 

Well, there are a lot of RS232 to 485 coverters out there... the one that I like the most is a NAM made by Carrier Comfort Systems. It's an externally powered and extremely robust converter. You should consider using it. I believe it retails for about 400 bucks from a Carrier distributor.

 

Only a simple question... What is Modbus RTU RS232?
Thanks!

 

Yes and there's quite a few products that'll do the job. I've used a product called a Gateway which does exactly that. More info at http://www.moxproducts.com

 

ModBus is a protocol
RTU = remote terminal unit
RS-232 is a type of serial communication

So, he has a device which utilizes the Modbus RTU protocol and it it has a RS232 serial data communication port

matt

 

Yes - provided all other thinks are taken care of (baudrate, station numbers, etc.)

Meir

 

There are a lot of products that are available to convert the protocal, but I believe the most effective and economical solution is an OPTO22. It gives you the ability to connect to an RS485 via the RS232 using either a 2 or 4 wire setup.