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Discussion Groups | Rabbit-Semi | modbus communication
This is a group for folks designing and programming embedded systems using the Rabbit Semiconductor C-programmable microcontroller. Rabbit Semi is a spin-off from Z-World who makes a variety of embedded modules and tools. This group is not affiliated with either Rabbit or Z-World, but is a user forum for sharing ideas, asking questions, flaunting knowledge, and other typical user group stuff. The Rabbit is a powerful uC, supported by a full-featured C-compiler.
modbus communication - oana chenaru - May 7 9:32:46 2008
Hello aganin
I want to implement a modbus communication between a PC and a rabbit. I have a modbus library and software on the rabbit and a ModbusOPCSrever on the PC. I put the same baud rate, parity, number of bits, address on both ends and it doesn't work. When I debug the rabbit software it seems it doesn't receive any packet.
Does anyone know where the problem might be?
Also, I am not sure if I configured correctly the RS232/RS485 converter, because I have to choose between DCE or DTE, between MON or SIM and between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE, MON and T-T-RTS (R-/RTS).
Thank you
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I want to implement a modbus communication between a PC and a rabbit. I have a modbus library and software on the rabbit and a ModbusOPCSrever on the PC. I put the same baud rate, parity, number of bits, address on both ends and it doesn't work. When I debug the rabbit software it seems it doesn't receive any packet.
Does anyone know where the problem might be?
Also, I am not sure if I configured correctly the RS232/RS485 converter, because I have to choose between DCE or DTE, between MON or SIM and between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE, MON and T-T-RTS (R-/RTS).
Thank you
____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
RE: modbus communication - Nathan Johnston - May 7 18:27:00 2008
Download a copy of ModbusPoll and ModbusSlave from
http://www.modbustools.com/ . They are invaluable tools for debugging
Modbus problems. I'd recommend you get it going with RS232 before trying
RS485 to simplify the problem initially as with RS485 you need to also
control (enable/disable) the transmitter and receiver. The RS232/RS485
converters often control the transmitter using the RS232 RTS signal.
Regards,
Nathan
-----Original Message-----
From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
On Behalf Of oana chenaru
Sent: Wednesday, 7 May 2008 4:24 PM
To: r...@yahoogroups.com
Subject: [rabbit-semi] modbus communication
Hello aganin
I want to implement a modbus communication between a PC and a rabbit. I
have a modbus library and software on the rabbit and a ModbusOPCSrever
on the PC. I put the same baud rate, parity, number of bits, address on
both ends and it doesn't work. When I debug the rabbit software it seems
it doesn't receive any packet.
Does anyone know where the problem might be?
Also, I am not sure if I configured correctly the RS232/RS485 converter,
because I have to choose between DCE or DTE, between MON or SIM and
between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
MON and T-T-RTS (R-/RTS).
Thank you
________________________________
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
it now.
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
http://www.modbustools.com/ . They are invaluable tools for debugging
Modbus problems. I'd recommend you get it going with RS232 before trying
RS485 to simplify the problem initially as with RS485 you need to also
control (enable/disable) the transmitter and receiver. The RS232/RS485
converters often control the transmitter using the RS232 RTS signal.
Regards,
Nathan
-----Original Message-----
From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
On Behalf Of oana chenaru
Sent: Wednesday, 7 May 2008 4:24 PM
To: r...@yahoogroups.com
Subject: [rabbit-semi] modbus communication
Hello aganin
I want to implement a modbus communication between a PC and a rabbit. I
have a modbus library and software on the rabbit and a ModbusOPCSrever
on the PC. I put the same baud rate, parity, number of bits, address on
both ends and it doesn't work. When I debug the rabbit software it seems
it doesn't receive any packet.
Does anyone know where the problem might be?
Also, I am not sure if I configured correctly the RS232/RS485 converter,
because I have to choose between DCE or DTE, between MON or SIM and
between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
MON and T-T-RTS (R-/RTS).
Thank you
________________________________
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
it now.
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: modbus communication - Jon - May 17 21:58:40 2008
You do have a bunch of work ahead. Start with RS232 to temporarily
avoid the hassles with the RS485 transceiver keying. Communications
is fussy - nothing happens until EVERYTHING is correct, and there are
few clues to tell you what's not right. Load up a couple demo modbus
things into your PC; I loaded a half-dozen and ended up buying
modbusview and calta, because they best served my needs. Read up
everything on the modbus.org site (the old standard is a little easier
to understand). If you can find another working modbus product (or
another PC with a modbus app) it really helps. Check out the layers
of the communications stacks, and figure out how to break the big
problem into little ones. I used to take a couple weeks getting
serial communications running, but have gotten better with practice.
DC's modbus stuff was good and got me going in a hurry. Once you get
it all going on RS232, you can deal with keying an RS485 transceiver -
not too difficult if you don't push the channel too hard. If you
really want to get the speed going, you'll need to dig and write a
couple lines of assembly.
Jon
--- In r...@yahoogroups.com, "Nathan Johnston"
wrote:
>
> Download a copy of ModbusPoll and ModbusSlave from
> http://www.modbustools.com/ . They are invaluable tools for debugging
> Modbus problems. I'd recommend you get it going with RS232 before trying
> RS485 to simplify the problem initially as with RS485 you need to also
> control (enable/disable) the transmitter and receiver. The RS232/RS485
> converters often control the transmitter using the RS232 RTS signal.
>
>
>
> Regards,
>
> Nathan
>
> -----Original Message-----
> From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
> On Behalf Of oana chenaru
> Sent: Wednesday, 7 May 2008 4:24 PM
> To: r...@yahoogroups.com
> Subject: [rabbit-semi] modbus communication
>
>
>
> Hello aganin
>
> I want to implement a modbus communication between a PC and a rabbit. I
> have a modbus library and software on the rabbit and a ModbusOPCSrever
> on the PC. I put the same baud rate, parity, number of bits, address on
> both ends and it doesn't work. When I debug the rabbit software it seems
> it doesn't receive any packet.
>
> Does anyone know where the problem might be?
>
> Also, I am not sure if I configured correctly the RS232/RS485 converter,
> because I have to choose between DCE or DTE, between MON or SIM and
> between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
> MON and T-T-RTS (R-/RTS).
>
> Thank you
>
>
>
> ________________________________
>
> Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
> it now.
>
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
avoid the hassles with the RS485 transceiver keying. Communications
is fussy - nothing happens until EVERYTHING is correct, and there are
few clues to tell you what's not right. Load up a couple demo modbus
things into your PC; I loaded a half-dozen and ended up buying
modbusview and calta, because they best served my needs. Read up
everything on the modbus.org site (the old standard is a little easier
to understand). If you can find another working modbus product (or
another PC with a modbus app) it really helps. Check out the layers
of the communications stacks, and figure out how to break the big
problem into little ones. I used to take a couple weeks getting
serial communications running, but have gotten better with practice.
DC's modbus stuff was good and got me going in a hurry. Once you get
it all going on RS232, you can deal with keying an RS485 transceiver -
not too difficult if you don't push the channel too hard. If you
really want to get the speed going, you'll need to dig and write a
couple lines of assembly.
Jon
--- In r...@yahoogroups.com, "Nathan Johnston"
>
> Download a copy of ModbusPoll and ModbusSlave from
> http://www.modbustools.com/ . They are invaluable tools for debugging
> Modbus problems. I'd recommend you get it going with RS232 before trying
> RS485 to simplify the problem initially as with RS485 you need to also
> control (enable/disable) the transmitter and receiver. The RS232/RS485
> converters often control the transmitter using the RS232 RTS signal.
>
>
>
> Regards,
>
> Nathan
>
> -----Original Message-----
> From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
> On Behalf Of oana chenaru
> Sent: Wednesday, 7 May 2008 4:24 PM
> To: r...@yahoogroups.com
> Subject: [rabbit-semi] modbus communication
>
>
>
> Hello aganin
>
> I want to implement a modbus communication between a PC and a rabbit. I
> have a modbus library and software on the rabbit and a ModbusOPCSrever
> on the PC. I put the same baud rate, parity, number of bits, address on
> both ends and it doesn't work. When I debug the rabbit software it seems
> it doesn't receive any packet.
>
> Does anyone know where the problem might be?
>
> Also, I am not sure if I configured correctly the RS232/RS485 converter,
> because I have to choose between DCE or DTE, between MON or SIM and
> between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
> MON and T-T-RTS (R-/RTS).
>
> Thank you
>
>
>
> ________________________________
>
> Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
> it now.
>
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Re: modbus communication - Md Kamel - May 17 22:26:49 2008
hi and hello evyone,
can any help me to guide as i am looking for a project to undertake ..
i am doing my msc,systems on chips for dsp and communications..
i have hands on fpga adv, matlab, c and java..
can nyone relate me some good and worth topics..
thanks,,and rpley to m...@yahoo.com
Jon wrote:
You do have a bunch of work ahead. Start with RS232 to temporarily
avoid the hassles with the RS485 transceiver keying. Communications
is fussy - nothing happens until EVERYTHING is correct, and there are
few clues to tell you what's not right. Load up a couple demo modbus
things into your PC; I loaded a half-dozen and ended up buying
modbusview and calta, because they best served my needs. Read up
everything on the modbus.org site (the old standard is a little easier
to understand). If you can find another working modbus product (or
another PC with a modbus app) it really helps. Check out the layers
of the communications stacks, and figure out how to break the big
problem into little ones. I used to take a couple weeks getting
serial communications running, but have gotten better with practice.
DC's modbus stuff was good and got me going in a hurry. Once you get
it all going on RS232, you can deal with keying an RS485 transceiver -
not too difficult if you don't push the channel too hard. If you
really want to get the speed going, you'll need to dig and write a
couple lines of assembly.
Jon
--- In r...@yahoogroups.com, "Nathan Johnston"
wrote:
>
> Download a copy of ModbusPoll and ModbusSlave from
> http://www.modbustools.com/ . They are invaluable tools for debugging
> Modbus problems. I'd recommend you get it going with RS232 before trying
> RS485 to simplify the problem initially as with RS485 you need to also
> control (enable/disable) the transmitter and receiver. The RS232/RS485
> converters often control the transmitter using the RS232 RTS signal.
>
> Regards,
>
> Nathan
>
> -----Original Message-----
> From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
> On Behalf Of oana chenaru
> Sent: Wednesday, 7 May 2008 4:24 PM
> To: r...@yahoogroups.com
> Subject: [rabbit-semi] modbus communication
>
> Hello aganin
>
> I want to implement a modbus communication between a PC and a rabbit. I
> have a modbus library and software on the rabbit and a ModbusOPCSrever
> on the PC. I put the same baud rate, parity, number of bits, address on
> both ends and it doesn't work. When I debug the rabbit software it seems
> it doesn't receive any packet.
>
> Does anyone know where the problem might be?
>
> Also, I am not sure if I configured correctly the RS232/RS485 converter,
> because I have to choose between DCE or DTE, between MON or SIM and
> between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
> MON and T-T-RTS (R-/RTS).
>
> Thank you
>
> ________________________________
>
> Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
> it now.
>
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
can any help me to guide as i am looking for a project to undertake ..
i am doing my msc,systems on chips for dsp and communications..
i have hands on fpga adv, matlab, c and java..
can nyone relate me some good and worth topics..
thanks,,and rpley to m...@yahoo.com
Jon
You do have a bunch of work ahead. Start with RS232 to temporarily
avoid the hassles with the RS485 transceiver keying. Communications
is fussy - nothing happens until EVERYTHING is correct, and there are
few clues to tell you what's not right. Load up a couple demo modbus
things into your PC; I loaded a half-dozen and ended up buying
modbusview and calta, because they best served my needs. Read up
everything on the modbus.org site (the old standard is a little easier
to understand). If you can find another working modbus product (or
another PC with a modbus app) it really helps. Check out the layers
of the communications stacks, and figure out how to break the big
problem into little ones. I used to take a couple weeks getting
serial communications running, but have gotten better with practice.
DC's modbus stuff was good and got me going in a hurry. Once you get
it all going on RS232, you can deal with keying an RS485 transceiver -
not too difficult if you don't push the channel too hard. If you
really want to get the speed going, you'll need to dig and write a
couple lines of assembly.
Jon
--- In r...@yahoogroups.com, "Nathan Johnston"
>
> Download a copy of ModbusPoll and ModbusSlave from
> http://www.modbustools.com/ . They are invaluable tools for debugging
> Modbus problems. I'd recommend you get it going with RS232 before trying
> RS485 to simplify the problem initially as with RS485 you need to also
> control (enable/disable) the transmitter and receiver. The RS232/RS485
> converters often control the transmitter using the RS232 RTS signal.
>
> Regards,
>
> Nathan
>
> -----Original Message-----
> From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
> On Behalf Of oana chenaru
> Sent: Wednesday, 7 May 2008 4:24 PM
> To: r...@yahoogroups.com
> Subject: [rabbit-semi] modbus communication
>
> Hello aganin
>
> I want to implement a modbus communication between a PC and a rabbit. I
> have a modbus library and software on the rabbit and a ModbusOPCSrever
> on the PC. I put the same baud rate, parity, number of bits, address on
> both ends and it doesn't work. When I debug the rabbit software it seems
> it doesn't receive any packet.
>
> Does anyone know where the problem might be?
>
> Also, I am not sure if I configured correctly the RS232/RS485 converter,
> because I have to choose between DCE or DTE, between MON or SIM and
> between T-RTS (R-ON) or T-ON (R-ON) OR T-RTS (R-/RTS). I set it on DCE,
> MON and T-T-RTS (R-/RTS).
>
> Thank you
>
> ________________________________
>
> Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try
> it now.
>
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )