Sorry I am having to repost this as I dont see the previous post anywhere, and this is sort of urgent for me. Is there some kind of a well documented example on how to use the modbus library MB ethernet master slave VIs to read from a modbus TCP connection? I have a Watlow EZ Zone PM controller using Modbus TCP protocol, and i know which registers i want to read to and write from, but I am not so sure how to make the required changes in the master slave VI, specially in the event structures. Could some one help me out please? I basically want to read from register 360 and write to register 2160 for now.
I'm trying to control the same controller via Modbus RTU. The only difference is my instrument's connection with PC is over RS-232 cable instead of TCP. I replaced MB Ethernet RW with regular MB RW vi. I was able to communicate with the controller. However, I received the same output values of holding registers for index 0 and index 1. I know that I would have an array of two 16 bit values from each register and I will have to convert that to a 32 floating point bit number to get the actual value of temperature. I believe all of my serial settings are correct but I don't know how to get these two values (given they are correct) and put out the wanted temp. Do you have any suggestion?
Take a look at the numeric/data manipulation palette. There are functions on there like join number where it can take two U16 elements and join them into a U32 element. Typecast is another function that can work.
thanks for the tip Ravens Fan, I was able to find the join number function in the pallete but then I don't know how to go from there to get the temperature value. I did some manually calculation from those values in array and convert them to hex then combine them in hi-lo order then convert it to 32 bit floating point then I would get the correct #. I' m not sure how to actually get it done in LabView. Do you have any suggestion?
