Hello, 

I want to control my SINAMICS V20 via terminal INPUT and AI0 in manual mode and in automat control via terminal input and SETPOINT via MODBUS. Manual mode works fine but in automat I can't write any Setpoint on the VFD.

These are the paramater I introduce in the VFD:

I can read all parameters from the VFD via MODBUS, but if I want to write SETPOINT for the VFD nothing happens. On the dispay appears 0.00 hz. 

1. I tried to write on the mb_address 40003 (FREQ REF) the value 10000 

2.mb_adresss 40101 (HSW) 1450 

3.mb_adress 40016 (REF FREQ) 5000 

always the same 0.00 Hz on the display 

does anyone have an idea what I am doing wrong? 

thank you!

This forum topic may help:

V20 CHANGE COMMAND SOURCE - 254806 - Industry Support Siemens

AutoGen_9130012

Hello, 

I want to control my SINAMICS V20 via terminal INPUT and AI0 in manual mode and in automat control via terminal input and SETPOINT via MODBUS. Manual mode works fine but in automat I can't write any Setpoint on the VFD.

These are the paramater I introduce in the VFD:

P700 – in000=2, in001 = 2

P0701 DI1- 1 

P0702 DI2- 29 

P0703 DI3- 9 

P0704 DI4- 99 

P1000 –in000=2 - in000 =5 - Selection of frequency (= 5: USS/MODBUS on RS485)

P2010 – in000 = 6 - Baudrate 9600 bps

P2014 – in000 = 3000 - Time to receive data

P2021 = 1 - MODBUS address for inverter

P2022 = 1000 - Maximum time to send reply back to the master

P2023 = 2 - MODBUS RTU protocol

P2034 = 2 - Parity of MODBUS telegrams on RS485

P2035 = 1 - Number of stop bits in MODBUS telegrams on RS485

I can read all parameters from the VFD via MODBUS, but if I want to write SETPOINT for the VFD nothing happens. On the dispay appears 0.00 hz. 

1. I tried to write on the mb_address 40003 (FREQ REF) the value 10000 

2.mb_adresss 40101 (HSW) 1450 

3.mb_adress 40016 (REF FREQ) 5000 

always the same 0.00 Hz on the display 

does anyone have an idea what I am doing wrong? 

thank you!

If anyone is looking for a solution to the problem;

You can write the speed setpoint by sending 16#047E to the 40100 (STW) register. Even if it is the terminal for control source, you need to set the necessary bits in the PZD data through modbus. (Control via PLC, enable setpoint etc.) After that you can write setpoint to 40101.