Hello,

I'm new to Modbus

I have a relay that I need to switch on/off
the relay is controlled by an ABB inverter.

the Modbus address in the inverter is 14.03 and I need to write to bit 13 in that address 0 or 1

how do I do it?

I have also found that in this address there are 36 option flags. so is it WORD or something else?

Thanks very much
Gil

 

The inverter/drive is a Modbus slave.

You need a Modbus master to initiate a write command to the slave.

A Modbus master can be part of an HMI panel, a standard or optional function in a PLC, a component in HMI/SCADA software, or the driver in an OPC server.

The Modbus master has some method to allow configuration or programming for which data needs to be read from or written to a slave. That involves complying with or specifying a choice of the format in which data is to be entered, depending on the master.

I'm not familiar with the address format 14.03. A link to the slave device's modbus map might clarify the address designation and the format for the 36 'option flags'.

 

Hi,

I'm using labview in order to write into the ABB inverter

The inverter/drive is a Modbus slave.

> You need a Modbus master to initiate a write command to the slave.

> A Modbus master can be part of an HMI panel, a standard or optional function
> in a PLC, a component in HMI/SCADA software, or the driver in an OPC server.

 

Hi.

Writing to 14.03 is not an issue I can handle it very easily from labview.

my question is how do I transfer bit13 to a number to be sent to the inverter.

Thanks,
Gil Maor

 

Not sure what drive you have. but in an ACS550, 14.03 is a configuration parameter for how the relays are to be controlled. You should fix this to 35 or 36, then alter 01.34 with an integer that represents a bit pattern of which of the relays you want on or off.

 

> Writing to 14.03 is not an issue I can handle it very easily from labview.

> my question is how do I transfer bit13 to a number to be sent to the inverter.

If I understood your question correctly, 8192 is the number you want to set for relay ON command if there are no other bit flags to set in the 14.03 word register.

 

>> Writing to 14.03 is not an issue I can handle it very easily from labview.

>> my question is how do I transfer bit13 to a number to be sent to the inverter.

> If I understood your question correctly, 8192 is the number you want
> to set for relay ON command if there are no other bit flags to set in the 14.03 word register.

Ok all I want to do is to activate a relay on the X22 so it will close a circuit.

This is supposed to be a very easy thing to do but when reading the manual I just can find the answer .

How can I do that?

 

> Ok all I want to do is to activate a relay on the X22 so it will close a circuit.

> This is supposed to be a very easy thing to do but when reading the manual I just can find the answer .

> How can I do that?

Force Coil 123 at Modbus Address 12 ON:
0C 05 00 7B FF 00 FD 3E

Force Coil 123 at Modbus Address 12 OFF:
0C 05 00 7B 00 00 BC CE

 

I'm very very sorry.

The relay is on X25 where the power (+24V) is connected to port 2, and the relay should close the circuit between port 2 to 3.

the communication is Modbus over Ethernet I have the RETA-02 module.

what would be the address and the address and the parameter sent.

Thanks
Gil