MOVE

[atomic_robo 0]

Hello all,

I am sorry in advance for asking such a noob question. 

I have a few Ethernet/IP stepper drives that I am controlling using nX1P2. Now, I am trying to execute 3 motions sequentially. It's not working. I have the logic attached in the pic. 

My idea was to use a ZoneCompare and when the motor is in that position it has to execute the next move. 

 

Any ideas why it's no working? 

Thank you a lot  

[Crossbow 295]

Looking at the picture none of the compares are within range.  Your current position shows as -200.012, just outside the second compare.

How fast is the value changing?  Is it possible it goes in and out of those ranges so fast the PLC doesn't have time to act upon it?

[Michael Walsh 268]

You may want to consider rounding (perhaps to the ones place though) as shown here:

http://forums.mrplc.com/index.php?/topic/34317-595000-czy-chodzi%C5%82o-ci-o-jak-mog%C4%99-zaokr%C4%85gli%C4%87-warto%C5%9B%C4%87-realu-do-2-miejsc-po-przecinku-how-can-i-round-up-the-real-value-to-2-decimal-places/#comment-160536

[innoaloe 59]

Considering you are using Ethernet/IP, usually aside from the Position Command, the Drives also have status bits mapped to the PLC Memory. Something like BUSY, FLAG, DONE, or whatever... It will be easier if you can use one of these status bits to check whether the first movement is completed, before giving the next movement instruction.

I'd say using Zone Compare is not a reliable method for Ethernet/IP because there is no guarantee that the data transmission is on a constant cycle, so the ladder program might missed some intermediate values

[atomic_robo 0]

Thank you all for your replies.