Here is my VI saved as LV8.6.
You've got some pretty wiring going on in your VI, but it is ridiculously unwieldy, not easily scalable, and uses some Rube Goldberg constructs.
Your Rubes:
1. Converty from Array to cluster to unbundle. Then bundling to go to a cluster then back to an array. No need to go through the cluster song and dance. You could have used Index Array and Build Array and not had to convert anything to a cluster or back,
2. Using a Dbl constant, than changing that to a Single by way of the Numeric conversion function in order to establish the data type for the type cast. Eliminate the conversion, and just set the representation of the constant to single precision instead of double precision.
3. Duplicating code dozens of times when it should have been handled in a loop.
If you use mine as a subVI, your screen real estate will be less than a 1/4 of what it is now.
Are you saying you need to read a bunch of registers that aren't adjacent to each other? You can do multiple read requests. Write a request command, then read the response. Then write another request command for different registers and read that response. It depends on how many different reads you need to do, or how far apart registers of interest are as to whether it makes sense. If you need to read a two pairs of registers that are some distance apart, it might be quicker to do a single read of multiple registers if they are close together and just throw away the registers you don't care about. It will be more bytes to read back, but it might be quicker since it can be done in only a single read. Or you could do two reads targeting your specific registers. It might be less bytes to read in each message, but it will take longer to do two read requests and wait for the responses in between.
I don't know if the limit of 125 registers is something do to your device, the modbus library, or modbus protocol in general. I want to say it might be the modbus protocol in general as 125 registers means 250 bytes of data. Factor in a few bytes for the response command and checksum, you'll be at 256 bytes. Modbus packets are designed to take less than 256 bytes so that only a single byte is needed to tell how many data bytes are going to be coming up in the message response.
With selective targeting of your registers to read, and using Index Array to read out the specific float32 values of interest, than you can write the desired 12 values to the file instead of all the ones you don't need.
