4/13/2012 8:07 AM | |
Joined: 4/22/2010 Last visit: 5/3/2024 Posts: 5697 Rating: (715) |
Hello, Should be o.k.but perhaps you need terminating resistors if not build in your devices. To read more you can read about Profibus, MPI these are both RS 485 connections. Or just google, sites like this can be interesting: http://en.wikibooks.org/wiki/Serial_Programming/RS-485 Regards, Marcjan |
Problem solved? |
|
4/13/2012 8:24 AM | |
Posts: 1547 Rating: (129)
|
Hi, for PROFIBUS a special compendium is available (let say it is the Bible). there you will find a section for electircal networks. Chapter 2.1 and chapter 7. SIMAITC Net PROFIBUS networks |
Last edited by: Rated X at: 4/13/2012 8:25 AM |
|
4/13/2012 3:35 PM | |
Joined: 8/18/2009 Last visit: 6/17/2024 Posts: 548 Rating: (33) |
dear smiffy, from serial port of PC I have connected to Moxa serial port.after I connected RS 485 port of Moxa(RS232 to RS 485Converter) to RS 485 port of ATC 1000(serial to ethernet converter). in same PC in ethernet port connected from ATC 1000. I have attached screenshot of setting in modbus poll & Modbus slave...same setting I have done in master & slave butCRC error & Bytes missing error comes in modbus poll. I have checked in hyperterminals( same setting done as a master & slave in modbus tool) then both side communication done ok. what is problem.....
Attachmenterror.zip (151 Downloads) |
Rajkiran Patil |
|
4/13/2012 4:24 PM | |
Joined: 10/7/2005 Last visit: 9/27/2024 Posts: 3023 Rating: (1054)
|
Hello RAJKIRAN I fear your ATC1000 is just a "dumb" Ethernet to serial converter instead of a Modbus TCP/IP to Modbusserial converter which would explain your problem. Even though Modbus on TCP/IPis essentially based on encapsulating a Modbus RTU message inside a TCP/IPframe, it doesso by stripping away the Address and CRC from the Modbus serial message and adds the so calledMODBUS Application Protocol header (MBAP) to it to create the Mdobus TCP/IP message (see www.modbus.org for all the gory details on this). The "conversion" froma Modbus TCP/IPto serial message and vice versa does as such need to be managed by the gateway and a simple Ethernet to serial converteris not capable of doing so. I suggest you do a search for Modbus TCP/IP to serialgateway (there's plenty of them available from various suppliers) and give it a try instead. I hope this helps |
Cheers |
|
This contribution was helpful to3 thankful Users |
Follow us on