Skid units connection, harting IO or ethernet

userxyz · Jun 17, 2020

Hi,

I may make an offer for a customer that needs 5 control cabinets for 5 skids and a main control cabinet for the PLC + HMI. They want to be able to connect to the main cabinet for automatic control to each skid, manual local control is with buttons and potentiometer for the speed of the onboard pump for example, in the local control case a connection to the main cabinet is not needed at that moment. The idea to connect to the main cabinet is with harting connections. I'm not really a fan of this concept, as you connect and disconnect signals for analogue and digital IO... connecting and disconnecting is not really okay IMO. Or you need to implement interface devices I think...

So, I was thinking in a different concept, to place a S7-1200 CPU in each cabinet and then with PUT en GET from the main cabinet do the communication. This way no IO on harting, only an ethernet cable...

My solution is more expensive offcourse, but its a more safe solution I think...

What do you guys think ?

Thanks,
Kind regards,
C

joaco1993 · Jun 17, 2020

Combo said:
Hi,

I may make an offer for a customer that needs 5 control cabinets for 5 skids and a main control cabinet for the PLC + HMI. They want to be able to connect to the main cabinet for automatic control to each skid, manual local control is with buttons and potentiometer for the speed of the onboard pump for example, in the local control case a connection to the main cabinet is not needed at that moment. The idea to connect to the main cabinet is with harting connections. I'm not really a fan of this concept, as you connect and disconnect signals for analogue and digital IO... connecting and disconnecting is not really okay IMO. Or you need to implement interface devices I think...

So, I was thinking in a different concept, to place a S7-1200 CPU in each cabinet and then with PUT en GET from the main cabinet do the communication. This way no IO on harting, only an ethernet cable...

My solution is more expensive offcourse, but its a more safe solution I think...

What do you guys think ?

Thanks,
Kind regards,
C

Hi, I had a very similar project using allen bradley. I did exactly that, put a compactlogix in the skid, which was connected using fiber/cooper to a contrologix.

Another aproach could be to use remote IO instead of a PLC in the skid..

In my project, worked great.

userxyz · Jun 17, 2020

Hi

Hi,

Thanks for your reply,
Yeah I was thinking also on remote IO as an alterantive, but when on profinet you get CPU errors if it does not match the hardware config, isn't that annoying ?

Thanks,
Kind regards,
C

joaco1993 said:
Hi, I had a very similar project using allen bradley. I did exactly that, put a compactlogix in the skid, which was connected using fiber/cooper to a contrologix.

Another aproach could be to use remote IO instead of a PLC in the skid..

In my project, worked great.

mk42 · Jun 17, 2020

Combo said:
Hi,

Thanks for your reply,
Yeah I was thinking also on remote IO as an alterantive, but when on profinet you get CPU errors if it does not match the hardware config, isn't that annoying ?

Thanks,
Kind regards,
C

THis is a potentially solvable problem. In the 1200, you can use D_ACT_DP to activate and deactivate devices. The PLC doesn't try to talk to a deactivated device, and no errors are reported if it is missing. Also, ET200SP allows you to do configuration control, where you can control which modules the HW config thinks is present by sending a data record.

Honestly though, a 1200 as remote IO (like you suggested) might be cheaper, and for a really simple application it might be simple enough.

Skid units connection, harting IO or ethernet

userxyz

Member

joaco1993

Lifetime Supporting Member

userxyz

Member

mk42

Lifetime Supporting Member

Similar Topics