lamboom

Omron NJ and EtherCAT LinMot Drive

6 posts in this topic

Hi... It's beginning to look like the the answer to the question "Can the NJ stream position data to a E/IP LinMot Drive" .. is NO    The NJ, using Ethernet/IP, can not produce Tag based data in constant cycles (which LinMot requires for streaming)  ...  CIP messaging doesn't look possible either.   However, over EtherCAT, the cyclic position data is constant, at 1ms, 2,ms or 4ms (with my NJ101-1000)  all within the range for LinMot streaming ... so they say... :-)

So now, I'm looking at using the EtherCAT port and the LinMot Drive C1250-DS .. an EtherCAT drive.. LinMot claims the drive will act as an Axis slave, just like Omron's G5 series motors. Which really work well when streamed with position data...

Has anyone ever used a EtherCAT LinMot drive with the NJ successfully?     Thanks much, Regards, Michael

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Hi Lam,

I don't want to start an industrial EtherNet discussion, but as you stated OMRON (who is ODVA member since very early stage, and knows very well CIP technology....) took the decission (for some good reasons...) to use EtherNet/IP for non time critical communications, and EtherCAT for RealTime control with a deterministic jitter of 1 us.

EtherCAT is designed or "realtime" with neglectible jitter communications, and the Sysmac Motion Control Engine is designed to work with EtherCAT in synchronous mode. EtherNet/IP Technology simply... can't do it..., so "motion control" based on CIP.... requires of different 'strategies'.. that can be Ok in some cases... but fail when high performance is required.

Sysmac uses DS402 Can Over EtherCAT Drive Profile, so... normally Drives following that standar (99% of EtherCAT Drives) should work.

Said that, I advice you to check

1) ethercat.org  list of compatible EtheCAT Drives, and check for it's conformance tests.

2) OMRON has it's own "test" laboratory, named 'tsunagi', purpose of this lab is to test and certify compatibility between OMRON Controller and 3rd Party Drives, therefore please ask your OMRON representative if the specific Drive has been tested by this 'tsunagi' laboratory, since normally they'd document any 'special' thing to be considered when combining NJ/NX with 3rd Party EtherCAT Slave.

Best Regards

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Hi  MotionControl.CAT ... Thanks much for your info..  I have quite a love for LinMot drives, and when I discovered the NJ, I just had to find out if they would work well together.

It looks like the E/IP port is useful for simple tag based applications using the LinMot linear motor.  The only reason I wanted to use the E/IP port for streaming position data... is because it was there, and I had an E/IP drive. (which is designed for streaming via E/IP) 

You aren't the first to try and pound some sense into my desire to answer that initial NJ/LinMot/EIP streaming question.  But, In my defense, Rockwell (Allen Bradley) has managed to do it using some clever Function Block and the drive's EDS file.. (it's beyond my limited ability to grasp .. sadly, I'm quite green when it comes to this technology)

I am aware of Tsunagi Labs .. and, it was suggested that I apply for an opinion from them.   However, I felt this E/IP thing didn't merit that level of attention by Omron.  I will continue to investigate the NJ's EtherCAT compatibility with the LinMot "DS402" drive  (C1250-DS-XC ..their model no.)     My use requirements are very reasonable, and not demanding in accuracy ... I'm just trying to make waves in a demonstration tank for science and educational purposes.  However, the waves are mathematically designed to model the real ocean.

Your  input is much appreciated.

Edited by lamboom

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PS:   In other words ... "high performance" is not really required...  but some level of performance would be nice... :-)

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UPDATE...The LinMot drive C1250-DS-XC is working well connected to the NJ's EtherCAT port..  Basic power-on, homing and move operations are working using the Sysmac FB's.

The big test is Position data Streaming ... with the MC_SyncMoveAbsolute FB ... Working on it ... :-)

Edited by lamboom

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Even more UPDATE..    I've managed to acquire a LinMot DS XC drive (CoE402)

Incredible as it might seem, the Omron NJ can create an infinitely long "Random Sea" position curve using the Drive as a slave:

                        59239a6cca6a9_plot1ms.jpg.fa1c07c769f037

I am not configuring the drive for Streaming Mode .. It is configured "Motion Command Interface" as a typical slave .. like the Omron G5 Servo motor.

However I'm having a small problem when that offset ramp reaches 50mm, and the curve starts at 50 and slowly builds to full height..  there is a "jump" at that point..which will become a thread soon, if I can't fix it... :-)

 

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