Sending Modbus message structure in LabVIEW 8.2

[evergood]

Hello

I'm going to ask a slave to send me some data from it's holding registers.

I'm using Labview 8.2 and have the modbus pack for 8.2.

I'm making a master program and want to send the following message 02,03,00,00,00,3c,45,e8 (HEX form) from the master to the slave. The slave program is made in C++ and can not be changed.

The problem is that I'm not sure where to insert the variables in the labview program.

Program code in the image below.

Thanks for helping me

Kris

[evergood]

Problem solved

[Ton Plomp]

Problem solved

What was the solution?

Ton

[evergood]

What was the solution?

Ton

I changed the serial parameters form RTU to ASCII, this gives the change to see the signal like HEX in the HyperTerminal i windows.

Then tried several setting until I got the right string in HyperTreminal.

What i got out was 02030000003CBF (wanted: 02030000003C45E8), you can se that its the same until ...3C.

The last 4 digits is the error check and found out that this not is the same in RTU and ASCII. (The error check is calculated from the content in the string.) More Modbus info: Modbus

Then tested the signal against the slave C++ program and got 60 numbers in return (now with serial parameters set back to RTU)

[stefvg]

I have a similiar problem. But i have to make connection first to another device how can i implement this?