Hello, You will need to download and install the ni_Modbus_8.2.exe and follow the instructions to install this for LabVIEW 8.5 There are examples on how you use the modbus vi's.
Christian A National Instruments Applications Engineer
Hello Nadz, If you take a look at the Master and Slave vi's there are case structures where input registers and coils are being read. Please go over these and let us know if you have any further questions.
Christian A National Instruments Applications Engineer
I'm using the same modbus drivers with and emerson AC drive, I have an issue when I'm trying to read negative numbers (data) from the registers i'm receiving the data as a U16. does anyone know if these drivers exist for signed integers as well or what the procedure would be to convert the modbus data recieve as signed integers?
PS . I have the NI Modbus library and my code works just fine when I'm moving in the positive firection the problem arises obviously when I reverse directions I receive a large number and even though it still sounts down.
The modbus library returns an unsigned integer that in your case needs to be converted to a signed integer. Just use one of the conversion functions located on the Numeric>Conversion palette change to a signed integer.
