G306 HMI to Unidrive SP comms

[ROAMER_AUS]

Hi

All suggestion thus far have all been valid. I would also go back and check all the tag values in the HMI to ensure you are not writing to the registers for the communication protocol.

Just A Suggestion
Tom

I loaded tmporary program that reads only one parameter from the drive. So eliminated that.

 

[ROAMER_AUS]

Been crook for last few days so no work on the problem. How ever I'll try to leave conerter in the circuit or use 232/485 converter and use 232 port on hmi if that does the trick. But I'm sure that it ia down to signal level. Pure electronics.

 

[osmanmom]

can you post the layout diagram

 

[ROAMER_AUS]

can you post the layout diagram

As in pinout connections?

 

[osmanmom]

node to node or port to port

 

[osmanmom]

rough sketch

 

[JHarbin]

Been crook for last few days so no work on the problem. How ever I'll try to leave conerter in the circuit or use 232/485 converter and use 232 port on hmi if that does the trick. But I'm sure that it ia down to signal level. Pure electronics.

The suggestion to include terminating resisters is probably the best one. Another option might be to add to signal isolator like the B&B Electronics http://www.bb-elec.com/Products/Ser...y-Isolated-RS-422-485-Repeaters/485OPDRI.aspx

This is just an option, I think the resistors *ought* to fix your problem.

 

[ROAMER_AUS]

The suggestion to include terminating resisters is probably the best one. Another option might be to add to signal isolator like the B&B Electronics http://www.bb-elec.com/Products/Ser...y-Isolated-RS-422-485-Repeaters/485OPDRI.aspx

This is just an option, I think the resistors *ought* to fix your problem.

Tried with resistors as well. No difference!

 

[ROAMER_AUS]

node to node or port to port

3 drives are connected to each other with all pins via a splitter
1-1-1
2-2-2
3-3-3
Etc.

One port from splitter is cable going to hmi. Pin 2 to pin 7 and pin 7 to pin 2. Splitter is basic 5 port spliter 1 to 1.

mind you this is original setup in the machine. Since then i tried various combinations. With pins 2 and 7 only. With /without splitter. With / without ground pins. With / without terminating resistors. Always the same result.

 

[osmanmom]

which one modbus master HMI or Siemens

 

[ROAMER_AUS]

Hmi is the master for drives comms. There is no problem with plc comms. It is on different port tough and doesn't use modbus for comms with plc.

 

[JHarbin]

Hmi is the master for drives comms. There is no problem with plc comms. It is on different port tough and doesn't use modbus for comms with plc.

Check private message

 

[JHarbin]

Hmi is the master for drives comms. There is no problem with plc comms. It is on different port tough and doesn't use modbus for comms with plc.

The manual says that it has to be daisy chained, not star, and that it requires terminals 2,3,7. are you connecting to those terminals?

BTW, I have my doubts that the splitter will work, if it is the kind I am familiar with it is more like a star network.

 

[ROAMER_AUS]

The manual says that it has to be daisy chained, not star, and that it requires terminals 2,3,7. are you connecting to those terminals?

BTW, I have my doubts that the splitter will work, if it is the kind I am familiar with it is more like a star network.

You are right. But this machine was working for 10 years with described setup. I have also tried daisy chain with no luck. Don't forget that unidrive doesn't communicate even when connected just to hmi,without other 2 drives. So star / daisychain really is not relevant yet. I have tried connecting ground pin as well. No difference.

 

[JHarbin]

You are right. But this machine was working for 10 years with described setup. I have also tried daisy chain with no luck. Don't forget that unidrive doesn't communicate even when connected just to hmi,without other 2 drives. So star / daisychain really is not relevant yet. I have tried connecting ground pin as well. No difference.

Not sure where to go with this, sorry. Not that it helps you, but I've daisy-chained 30 Modbus devices to a similar Redlion device without even terminating resistors.

You could try the isolator I suggested before. I've never needed it for Redlion equipment, but have needed it for other Modbus Masters.