Modbus libraries for LabView 8.0

[gdah]

hi...i stil have the same problem..didn't found any solution to solve this problem. i realize that there is no reveice modbus frame when i send multiple data. i think that device cannot recognize more that 13 byte modbus frame.

[Donovan_B]

Hi gdah,

What value is currently set for the timeout in your code?  You might try increasing the timeout value because, depending on your SPR, it may take more time to receive the data than your code is currently allowing before timing out.  If this does not fix the error, you might post your block diagram, or at least a screenshot of it, to see if we can figure out why this is happening.

[Pets65]

Hi,
I've read your old message. I have some troubles with an acs350 + FMBA-01 module.
It seems that the module is not correctly initialized.

Do you have any hint to right configure the acs?

Tnx
Pets

[Brian_Beal]

I don't have a manual with me, but I believe that the comms are set up in group 50.

[DevinChen]

Hi Nishant,

I read through some of your posts regarding the communication of the Omega CN 9600 series temperature controller and I am wondering if you got any further progress with Tony Asn as I need help using labview to acheive the same-reading the temperature off CN 9600.  As a new user to Labview and programming, I followed a device communication setup for the touchscreen sample, setting up the slave and the master, but I only need to read off values. So if I only need to read off the values, do I only need to include a read all to holding registers?  Sorry, please explain to me if you can, I really appreciate it.

Devin

[Hsien]

Hi Peder,

Could you post the vi you made it worked?  I am using ABB ACS550 and also stuck.   I think it should be the same for modbus communication in ACS550.  Much appreciate,

Thanks in advance,

JIM

[Brian_Beal]

Jim-

The ACS550 has built-in Modbus, and does not use an external module, so the setup is a little different.  Communications from Labview would be the same, though.  Are you using the NI Modbus toolkit?

[Hsien]

Hi Brian,

I am using the MB Serial Master Query.vi, and can only read (or say I only know how to read) the holding registers.  I am trying to write command to ACS550 to start/stop the derive and ramp up the frequency but get stocked.  I use the function code " write single register".  Any help would be very appericate.

Thank you

Jim

[Brian_Beal]

Jim-

Once you set up all of the drive parameters for controlling using fieldbus, you just need to manipulate the control word to start and stop the drive.  There is a state machine diagram to use that sets the control word bits and looks at the status word, then sets the control word, etc.  The "quick" way is to first set the control word to 1143, then to 1151 to start it.  Change back to 1143 to stop it.  ABB has some documentation that explains things in more detail on how to control using communications.  Contact your ABB rep or distributor to get those documents.  Where are you located?

Brian

[Hsien]

dear Brian,

My location is in Woodland CA 95776. ,

I have set up the drive parameter codes (5301 to 5305, 1001~1003, 1601,1604 and 1607) as indicated by the manual.  Sorry for the tedious bothering as i assumed you know the ACS 550 well.  I found the state machine table) on the manual (a 16 bits unit) but not sure how to manipulate it.  The control word you said for the 1143 and 1151, where shall I put them in the vi?  Also, which function code shall I use?  I use the MB Serial Master Query.vi in the lib.    

Thank you a lot,

Jim