G306 HMI to Unidrive SP comms

Hi All,

I know this is a PLC forum, my system does have a PLC but it's not part of the problem.

I have Redlion G306 HMI communicating with Siemens S7 PLC on RS485 port and to 3 Drives on RS485 port on option car installed in HMI.

Comms to drives is Modbus RTU on 19200 bps.
Drive #1 address 1: Unidrive SP configured for closed loop servo mode with EZ motion blue module.
Drive #2 address 2: Commander SK
Drive #3 address 3: Commander SK

This was all working fine untill I came yesterday to do some modifications on the HMI (adding one toggle button) and adding some timers in PLC.

When I did my changes in Crimson 2 software for HMI and uploaded them, software automatically proceeded to update the firmware on HMI as well. All comms cables were connected at them time. At this stage I didn't make much note of it because HMI came up good. After finishing other work with PLC I wanted to test whole machine (this was about 3 hrs after uploading to HMI) and then I found out that there is no comms between HMI and drives. After investigating I found that drives were all of a sudden with following settings
Drive #1 Address 1 speed 9600 bps
Drive #2 Address 1 speed 19200 bps
Drive #3 Address 3 speed 9600 bps
Imagine my superse!!!
So I put them all back to what they are supposed to be and got comms from #2 and #3 but not from #1.
When I disconnect #1, #2 and #3 communicate with HMI, but with #1 plugged in, none of them work. #1 doesn't communicate even even connected just by itself to HMI.
Drive #1 how ever communicates when connected to laptop with CTsoft or PowerToolsPro software.

Now, I'm tipping that firmware update sent whole lot of corrupted data on the port somehow, or something else misteriously happened?

PLC comms works fine.

Does anyone have any idea? Experienced something similar before?

Best regards, and thanks!!!

I have not used the uni drives with the red lion.
I have seen this behavior before from the HMI. I usually load the program a second time. This takes care of any firmware issues.

Did you cycle power on the HMI?

JeffKiper said:

I have not used the uni drives with the red lion.
I have seen this behavior before from the HMI. I usually load the program a second time. This takes care of any firmware issues.

Did you cycle power on the HMI?

Click to expand...

Thanx for the reply!

Yeah i did power cycle and reloaded the program a few times. I don't think that hmi is the issue since it communicates with other 2 drives via same port.

i don't know much this stuff,

but if you have save the parameters Uni drive SP #11.23-#11.25,how the parameters change ?

after recycle Unidrive SP are this parameters still same ?

Well that's part of my problem. I can't figure out how or why these parameters changed. They were saved in the drives.

Does anyone know if unidrive can be set as modbus master? I didnt see any parameters for this.

I had a similar problem where my uni drive was putting values in at random. What i did is take the smart card and write the correct values to the card. Then set the drive to load these settings in at boot. Never had a problem after that.

Hope that helps

Interesting brettshelley, thanx for the idea. I'll have to do more interrogation and try to find some sense in this problem.

The Unidrive can only be a Modbus Master with a Coprocessor, like SM-Apps module. The EZ Motion module wont quite do it...

Gene Bond said:

The Unidrive can only be a Modbus Master with a Coprocessor, like SM-Apps module. The EZ Motion module wont quite do it...

Click to expand...

Thanx Gene,

I was asking just in case there is a setting that can make it a master or for system to think that it is a master. In this case I need it to be a slave for sure.

Partial problem found!!! Looks like there is a hardware fault in the Unidrive SP port. How ever it can work in some cases. For example if I connect just unidrive and HMI, no comms, but if I add USB to RS485 adapter from my laptop to the comms bus... BANG... it starts working normally. So this adapter probably changes impedance of the circuit or suppresses some noise on the signal or something like that.

Did anyone have similar problems to this?

Do you have the 120 Ohm terminating resistors in place?

i think something not right here.

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

Just throwing this out there.
The Eplison EP-P & FM4E drives can be setup as Modbus Masters see Application Note PTAN #3, rev.2.
Tom

JeffKiper said:

Do you have the 120 Ohm terminating resistors in place?

Click to expand...

Tried with and without. No difference!