doki

hi,

I knew the problem
The problem was Visa laibrary is not installed

in the modbus manual

Example 1 - Actual Data (3X References)
To read actual parameters 2 and 3 (Current and Voltage, addressed as 1 and 2 hex) of the
RVS-DN with a serial link number of 18, the host computer should send the following frame:
byte 1: Serial Link No. ($18)
byte 2: Function ($04)
byte 3: Starting Address High ($00)
byte 4: Starting Address Low ($01)
byte 5: No. of Points High ($00)
byte 6: No. of Points Low ($02)
byte 7: CRC_Low ($XX)
byte 8: CRC_High ($XX)
The RVS-DN response, (when Current = 400 % of FLA, and Voltage = 420V) is:
byte 1: Serial Link No. ($18)
byte 2: Function ($04)
byte 3: Byte Count ($04)
byte 4: Data High, parameter 2 ($01) (400)
byte 5: Data Low, parameter 2 ($90)
byte 6: Data High, parameter 3 ($01) (420)
byte 7: Data Low, parameter 3 ($A4)
byte 8: CRC_Low ($XX)
byte 9: CRC_High ($XX)
Note: $XX indicates Hexadecimal byte.

Do you write the address as a string, such as 180400010002 first calculat crc and write crc low& high in the string

Is there a way to calculate the crc directly without the need for computed
What are the functions necessary

have to communicate with the device via the opc server

But I want to connect to the device  by LabVIEW

Error -1073807202 occurred at VISA Open in GPIB-VISA.vi

I need to help you to work project by LabVIEW

Idea of the project

Work on the external interface to control the Ketrical of Board of Water Pump

Electrical board contains

 Soft starter a type: RVS-Dn 72 , solcon
Frequency converter type: VFD 075E43A , delta

I want to first:
A connection to soft starter and frequency converter "inverter" via RS485 link use Mod Bus Protocol

work GUI for soft starter:

The  main menu contain several keys to work
Run ,START, soft START, stop , soft stop and Rest in the event of an Alarm and show the value of voltage and current.

The second list contain  parameter settings to read values and work setting "write" .

The third spectrum describes plant for voltage and current.

The same way we do for frequency converter but the main menu contain  keypad to work high speed , low speed , run , stop

Added menu enables  to work sequence  certain for work different  movements

Lab View contains a library of Mod Bus Protocol
I do not know how to use it
I have manual for mod bus soft starter and frequency converter

DN_Modbus.pdf