Need a little modbus TCP help

[haluk]

RavensFan

You are right.  I clean the rest of the VI and it reads ok now.

The address is 4096 (not 4097)

Thank you all.. attached the vi that works.

[haluk]

attahment- second try

[andre.butler@neo.edu]

All I am trying to do is try to read the holding register from this chiller unit but I keep getting this error. I try pinging both address and they seem to be working fine. Is there anyone that can help assist me with my issue?

It would be greatly appreciated

[andre.butler@neo.edu]

All I am trying to do is try to read the holding register from this chiller unit but I keep getting this error. I try pinging both address and they seem to be working fine. Is there anyone that can help assist me with my issue?

It would be greatly appreciated if anybody has any suggestions.

[RavensFan]

I don't see where you are trying to read a holding register.  You have two functions,  one reading coils and the other reading input registers.

[andre.butler@neo.edu]

Thank you for the response andI circled it in paint. I am just trying to read the analog values regardless of what the numbers look like. I am really just trying to see some result/indication of numbers.

[andre.butler@neo.edu]

The coils are digital outputs and the input registers are the analog values

[RavensFan]

Your indicator is called Holding Registers, but the data is coming from the polymorphic Modbus VI that you have set to Read Input Registers.   Input registers and Holding registers are different.  The name of the indicator doesn't matter at all.  But if you are trying to access a holding register, but are using the input register function, then you will get an error.

Also be sure that the parameters you are feeding into the function are correct.  For instance, the constant 65535 seems rather large. I can't tell from your screenshot what constants go where since many of your wires aren't straight or are running backwards.  Try using the block diagram cleanup tool on the toolbar.

[andre.butler@neo.edu]

Okay thank you very much. Attached is me changing the read input registers to holding registers so that I may be able to read values from my modbus so I put an array indicator to do so. my 65000 thousand value was just me testing values out so that I may find a solution but the same error occurs when I have  a small value or large vaule there. I just keep getting this error 6002 

[RavensFan]

You have both coils and registers starting at address 0.  That may be possible, but on many devices, it is not.

Have you read the communications manual for the device?  Have you tried using any 3rd party modbus monitoring programs to see if they work?

Try attaching a link to the manual.  6002 is for an invalid address.  So I'm suspecting you are callling out the addresses properly in your VI.

Here is a document that can help you understand the modbus protocol.  http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf