Delta MS300 VFD, RS485, RPI4, QTdragon, getting it to work

The names and types of pins created by Mb2hal is determined by what you put in the Mb2hal ini file. Specifically the transactions that you define there. 
There are at least 5 different transaction types that can be used. And these  determine if the pins created are boolean, floats, # inputs or outs.
fnct_02_read_discrete_inputs: creates boolean output HAL pins.
fnct_03_read_holding_registers: creates a floating point output HAL pins. also creates a u32 output HAL pins.
fnct_04_read_input_registers: creates a floating point output HAL pins.also creates a u32 output HAL pins.
fnct_15_write_multiple_coils: creates boolean input HAL pins.
fnct_16_write_multiple_registers: creates a floating point input HAL pins.

The number of hal pins created by each "transaction" is determined by the number of "elements" in that transaction.

The names of the hal pins created are the default name:
Example pin name for the 1st transaction 2nd element would be:
mb2hal.00.01 (transaction=00, second register=01 (00 is the first element))
or the transaction number can be replaced by name you define with
HAL_TX_NAME=name
Would give: mb2hal.name.01

Setting up modbus communication for a new device you aren't familiar with is always a pain. (even when you do know what you're doing.) The documentation for the device is almost always universally awful, worse if it is Chinglish. From the looks of it your life is going to be made difficult by the fact that according to that document the drive only supports modbus functions 3 and 6. So you won't be able to address individual bits directly or read/write to multiple addresses. The first issue will result in you having to set up hal components to translate bit io to and from S32 integer numbers. The second problem will make you have to set up individual transactions for each different register you may need to access on the drive. That can lead to slower communications, especially if you must communicate with multiple devices.

So for example you'll need to set up a transaction that writes to 1000h (That would be 4096 in dec and I think the address number you'll need to use in your modbus ini file.) But you will have to send to that transaction an integer number representing the state that you want the drive set to, fwd=1, rev=2, stop=5... One of the mux hal components might be useful for setting the value you want for the appropriate bit inputs. (It doesn't look like simple binary bit/coil translation will work for this register.)

fnct_03_read_holding_registers (03 = 0x03)
fnct_06_write_single_register (06 = 0x06)
fnct_16_write_multiple_registers (16 = 0x10)

Calysto wrote:

I'm just talking to myself, that helps too