AB POINT IO 1734 USED FOR LIMIT SWITCH XMIT

[josedavidch]

Hi all..

I have an application where the actual handler moves a vertical system powered by a MP series motor from AB. Motors are driven by sercos Ultra 3000. PLC is a 1768-L43 with motion module SERCOS. Since the 3 stations are inside a medical explosion-risk (class1, div 1)room , the main enclosure for PLC, drivers and other control devices are out and far away from the actuators. Every machine uses a Panel View PLus 1000. So, I was asked to use IO Point for future expansion on this machine, now I am wondering how good idea could be to use this IO Point 1734 input module to handle 3 signals back to PLC and then to Ultra3000 if needed: Driver Enable, Limit + and Limit -. The idea is to take advantage of the Ethernet cable that will be on every station for the HMI and hook the 1734 to it and save a long run of control cables from main enclosure to handle these signals.

As some of you know, the Sercos driver can be setup to "see" movement limits withing the set movement range, so this can be also used as limit +/- in case of need. Thats another option.

So, I want to read some good cons-pros of using:

1-Limit +/- switch and driver enable thru Ethernet from actual machine to main enclosure
2-Using the software setup limit +/- to limit the actual vertical system movement.

 

[controlsdude]

Problem with this idea is that sercos on ethernet just like ethernet IP needs a dedicated network to make it close to being deterministic. Since your talking servos on a sercos network, I think even having the HMI on it would make it unstable sercos network.

If you ran a seperate ethernet cable out then I think it would be a stable sercos network using the point IO 1734-AENT.

But if you still want to do this there is a lock step firmware that you need to follow for the 1734-AENT to firmware 2.003. refernce this pub 1756-rn642_-en-e.pdf

 

[josedavidch]

Thx.
Just to clarify:
-HMI and point IO will run separated ethernet cable
-Ethernet network is dedicated for this equipment
-Sercos network is fiber optic type and runs from plc to the three ultra3000 drivers. Driver and plc are within 1 meter

 

[controlsdude]

I thought the new Sercos 3 was an Ethernet wrapped protocol?
So this was not what your talking about above?

On page 6 of the PDF they are saying Sercos 3 is behind its own router.

On page 11 of the PDF they are saying the HMI needs a seperate Ethernet away from the Sercos network.

http://www.sercos.com/literature/pdf/sercos3_en.pdf

Like I said before Sercos drive, IO, controller, safety on seperate network from HMI. I think the PDF is saying that too.

So you would have an Ethernet card or sercos specialty card coming out of the local rack that the processor is in dedicated to Sercos 3, then another Ethernet card for the HMI and programming and plant communications.

devil is in the details!! at least thats what some professor and engineering managers always beat into me over the years.

 

[josedavidch]

Thx.
Sercos does not run over ethernet, at least this model I Have. Its own network is made by linking the drivers with fiber optic cable in a daisy-chain basis. This fiber optic runs from motion module on PLC thru every driver.
My idea is to use the 1734-AENT with a 1734-IB8 to get the inputs from limit switchs and driver enable on the machine and send this signals thru ethernet to the PLC, then from PLC send to the sercos what ever I need.

 

[controlsdude]

Before you get to site run an offline configuration with RSNetworx for Ethernet or use this ethernet tool to verify that the network performs at the RPI rate that you want the remote IO to perform to a spec.

Ethernet Performance tool

http://www.rockwellautomation.com/solutions/integratedarchitecture/resources3.html

 

[PLCMentor]

I have to ask - are you using the PV1000+ in the C1,D1 room? If so how have you isolated it from the environment?

Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com