Max # of AB 755 drives on 1756-en2t

The literature states "128 axis _CIP_Drive configurations based on Ethernet TCP Connections. Of those 128, 8 Position loop axes maximum." Does this mean I can have a max number of 8 or some number up to 128 drives on the 1756-en2t with l71 processor. This is for a 3 to one merge conveyor system.

I currently have (8) 755 drives and (4) 525 drives on a single 1756-en2t and started experiencing faults.

Thanks

Hi

What are the faults you are getting. What Processor are you using and what firware is the cpu and the Ethernet card. With the current number of vsd's you should have no problems as I have carried out much larger installs with no errors once I get it running


Donnchadh

All the drives are shutting down with F73 code. Processor is an L71. Not sure on the firmware v, if that is critical I can find out, but it was installed in the last 6 months.

What is your network topology?

Keith

ethernet running from en2t card to eds-516a managed 16 port sw, indiv drives are connected to ports on the switch. Drives are all under 25' to the indiv motors.
thanks

That is an adapter card fault. What card is in that slot?

PowerFlex AC Drives: Port Adapter Faults F71, F73,F75 or F76
66126 | 01/13/2010 | Access Level: Everyone

Originally posted by rdrast:

That is an adapter card fault.

Click to expand...

Unless he is referring to the PF525's, in which case it is an embedded Ethernet port comm loss fault.

You are down to three components:
the EN2T, the switch and the cable between them.

Cables are easy to change; I would start there.

If you access the EN2T webpage there is a diagnostics section that will tell you what the loading is on the EN2T. You might want to check that but I really believe it will show a very low percentage of loading.

There really isn't much the plc can do you cause a loss of comms to all the drives but I may be wrong there.

And then there is the switch. You might want to see if the switch serves up a webpage with any kind of information.

Keith

jkerekes said:

PowerFlex AC Drives: Port Adapter Faults F71, F73,F75 or F76
66126 | 01/13/2010 | Access Level: Everyone

Click to expand...

In case you didn't catch that, it's a Rockwell Knowledge Base article. Available here: then search for the article number he showed, 66126

If you are not already registered, you need to, but there is no cost.

Hi

I would start by removing the managed switch and use an unmanaged switch.
I would also check the cables.
Is this a new install or has it been working?

Donnchadh