Setting up USB -> Modbus (CH340) for VFD control

lsusb

bridgeport@bridgeport-H81M-S2PH ~ $ lsusb Bus 002 Device 002: ID 8087:8000 Intel Corp. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:8008 Intel Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 006: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter Bus 003 Device 005: ID 222a:0045 Bus 003 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter Bus 003 Device 003: ID 10ce:eb70 Silicon Labs Bus 003 Device 002: ID 1c4f:0034 SiGma Micro Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 003 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter

[MB2HAL_INIT] INIT_DEBUG=0 . HAL_MODULE_NAME=mb2hal SLOWDOWN=0.0 TOTAL_TRANSACTIONS=3 # Set Run Status [TRANSACTION_00] LINK_TYPE=serial SERIAL_PORT=/dev/ttyS0 SERIAL_BAUD=9600 SERIAL_BITS=8 SERIAL_PARITY=none SERIAL_STOP=1 SERIAL_DELAY_MS=3 MB_SLAVE_ID=1 FIRST_ELEMENT=7680 NELEMENTS=1 MB_TX_CODE=fnct_16_write_multiple_registers HAL_TX_NAME=run MAX_UPDATE_RATE=0.0 DEBUG=3 # Set Frequency [TRANSACTION_01] MB_TX_CODE=fnct_16_write_multiple_registers FIRST_ELEMENT=7681 NELEMENTS=1 HAL_TX_NAME=frequency MAX_UPDATE_RATE=0.0 DEBUG=3 # VFD Status [TRANSACTION_02] MB_TX_CODE=fnct_02_read_discrete_inputs FIRST_ELEMENT=0 NELEMENTS=16 HAL_TX_NAME=is-running MAX_UPDATE_RATE=0.0 DEBUG=3 #REQUIRED: Modbus transaction function code (see www.modbus.org specifications). # fnct_02_read_discrete_inputs (02 = 0x02) # fnct_03_read_holding_registers (03 = 0x03) # fnct_04_read_input_registers (04 = 0x04) # fnct_15_write_multiple_coils (15 = 0x0F) # fnct_16_write_multiple_registers (16 = 0x10) #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 pins are named based on component name, transaction number and order number. #Example: mb2hal.00.01 (transaction=00, second register=01 (00 is the first one))