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Old May 18th, 2018, 02:19 PM   #16
technolog
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I think We've convinced our Rexroth vendor's sales engineer that we can't use Rexroth's "Freely configurable mode" because we only have explicit messaging available to us. He was hanging his hat on that as it seems to be the only mode of operation he's somewhat familiar with. We think there are other modes in the drive that we can use to get it talking and exchange the meagre amount of data we need.

I'll bear in mind the safety concerns and make sure we check what happens when the ethernet cable is unplugged. Does this perhaps suggest the use of a "heartbeat" signal to make sure the comms is up and running?

Thanks for all the help proffered so far, I'm sure I'll be looking for more assistance soon.
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Old May 18th, 2018, 03:40 PM   #17
Ken Roach
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One of the Rockwell commercial engineering guys had a saying about this sort of thing: "No matter how low or how slow you try, a crocodile will never fly".

Cyclic I/O simply isn't a feature that the SLC-5/05 or MicroLogix 1100/1400 support.

Some devices require a true cyclic I/O connection to be established and running, while some will allow you to read and write the same data objects (that would usually be connected to a cyclic connection) using acyclic messages.

I'm a notable critic of such messaging methods, because they aren't intended to work that way. They require that you take extra care with timeouts and failure modes and considerations for sharing the resources of the controller with other features (HMI, online editing, etc).

And part of the practical problem is that it's usually novice programmers who get themselves into a situation where they have an SLC-5/05 instead of a CompactLogix, and they aren't suited for the challenge of that extra programming.

The compromise I aim for is that the Start/Stop commands be hard-wired, and the setting of position or velocity setpoint values be done using messages.
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Old May 21st, 2018, 07:44 AM   #18
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Thanks for that, Ken. There's no rush on this project at the moment, so we have the luxury of being able to 'play around' with the explicit messaging to see if we can get it to work safely and reliably. If not, we have the fallback position of hard-wiring.
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Old Yesterday, 06:31 AM   #19
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We have a 1769-L35E processor. It appears to be capable of doing the implicit messaging. Our AB vendor has said "The L35E controller is older technology, my recommendation is to use the 1769-L30ER(M) or the 5069-L306ER(M)". He doesn't confirm that it's capable of doing what we need or that it's not and he has a vested interest in selling us new processors. Can someone confirm that the L35E will do what we need, please?
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Old Yesterday, 09:02 AM   #20
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Yes the L35E can do Cyclic I/O or Implicit Messaging.

You can only flash the L35 up to version 20 of Firmware, so you will want to make sure any AOP or AOI that you can get from Rexroth is compatible with that version of Firmware. Most likely it is but just make sure.
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Old Yesterday, 11:46 AM   #21
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The 1769-L35E was the first very popular CompactLogix controller.

It has some older technology (only up to v20 firmware, serial instead of USB, no safety or motion) but its basic EtherNet/IP I/O functionality is the same as its modern cousins.

While I wouldn't buy a 1769-L35E to sell to a customer on a brand-new machine, for an in-house control project I wouldn't hesitate to use one.
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Old Yesterday, 01:24 PM   #22
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Thanks, Ken.
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Old Yesterday, 02:57 PM   #23
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Indeed, very interesting thread
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Old Yesterday, 08:38 PM   #24
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What is the complete PN of your drive and what is the PN and Firmware version of the control section with motor information? Not completely familiar with the IndraDrive Cs. Have only used the IndraDrive C series HSC02.1.



In the past using the Indradive C for a highly accurate shaft turner (non Coordinated motion). With the HSC02.1 there is an Encoder Emulation Output that can be connected to a high speed input module and the speed can be controlled via analog output. This all depends on the PN and firmware of the control module.


Not sure your application requirements but if its simple control there may be no need for EthIP communication.


Also what SW are you using to configure the drive? Indraworks engineering, IndrawroksDS?



Quote:
Originally Posted by technolog View Post
I think We've convinced our Rexroth vendor's sales engineer that we can't use Rexroth's "Freely configurable mode" because we only have explicit messaging available to us. He was hanging his hat on that as it seems to be the only mode of operation he's somewhat familiar with. We think there are other modes in the drive that we can use to get it talking and exchange the meagre amount of data we need.

I'll bear in mind the safety concerns and make sure we check what happens when the ethernet cable is unplugged. Does this perhaps suggest the use of a "heartbeat" signal to make sure the comms is up and running?

Thanks for all the help proffered so far, I'm sure I'll be looking for more assistance soon.

Last edited by matthew1; Yesterday at 08:44 PM.
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Old Today, 03:27 PM   #25
technolog
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The drive part # is HCS01.1E-W0054-A-03-B-ET-EC-NN-NN-NN-FW

I don't know what the control section part # is but suspect it may be specified by the main part #. I know the firmware is V18

I'll try to get the motor part # tomorrow. They're old Allen-Bradley drives which we had to change out the resolver on to get them to be controllable from the Rexroth drive.

The application is fairly simple. We just want to be able to tell it to Home, Jog, and move to a position. We need to command velocity and give positions to move to. As for status information, we need position feedback, Homed, In Position, that's about it.
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