PLC5/30 comm to Micrologic

[Mickey Mills]

I have a PLC5/30 connected to a local HMI thru DH+ to KTZ card.
Would like to add Micrologic stand alone controller. Distance to HMI
prohibits running new comm link to Microligic but would like to view
data from new controller. What would be my options to conncet to
PLC5/30. I would prefer not to use RS232 (leave for programming and troubleshooting port)?

 

[Mickey Mills]

Sorry should have been KTX card

 

[Ken Roach]

Since it's a new MicroLogix, it will support DH-485 protocol, so you can use a 1785-KA5 DH+/DH485 bridge and a 1761-NET-AIC converter.

It's more expensive than the MicroLogix, though !

If you need to proof this out before requisitioning a network bridge, there's a KA5 is our training demo stock that I can swipe for an evening.

 

[Mickey Mills]

Thanks, I checked price (wow) I probably could run new comm link
for that cost
Mickey

 

[JesperMP]

Hi Mickey,

what are you trying to do ?

If you want to communicate between the PLC5/30 and the Micrologix,
1. Use a 1785-KA5 DH+/DH485 bridge plus a 1761-NET-AIC as mentioned by Ken.
2. Sacrifice the serial port on the PLC5/30 for a direct connection to the Micrologix. Invest in a DH+ card for your troubleshooting so that you can connect to one of the DH+ ports (a good investment to my opinion).

If you want to add the new Micrologix to your HMI, then you have several options:
1. You can connect via the bridge as mentioned above.
2. If your HMI supports several communication channels at the same time, then you might consider to run a separate line to the new Micrologix. If the distance requires it, you might need to have 1761-NET-AIC at both ends (or 1761-NET-ENI maybe).

 

[JesperMP]

I can't get this post out of my head...

what are you REALLY trying to do ?

Is the new Micrologix for a completely separate function or proces and do not have anything to do with the function or proces that is controlled by the PLC5/30 ?

If yes, then go ahead with a new and separate PLC.

But if on the other hand you are trying to expand the existing control system that is handled by the PLC5/30, then try at all cost to keep it within the existing PLC5/30.

- The PLC5/30 is better than the Micrologix (it has online editing).
- You will keep the existing HMI connection.
- The system will be functionally simpler and be easier to maintain.
- With everything added up, it will be cheaper than adding a Micrologix PLC and new communication hardware.

To connect the existing PLC5/30 to the new functions, you have several options.
1. Add new i/o-modules in the existing rack if possible. Connect via terminals and cables.
2. Connect via the free DH+/REMIO port on the PLC5/30 CPU to either Flex i/o or Compactblock i/o (whichever suits you best).

 

[Mickey Mills]

Hi JesperMP
Thanks for advice. The system that the new controller is going to
control is a vapor recovery unit very critical, my thinking was
not to have all eggs in one basket. The option to use PLC5/30 with
Flex I/O is one that I have considered. Probably the way to go.

Mickey

 

[JesperMP]

Hmmm...

I have to admit, if the system is very critical, and it might happen that the PLC5/30 system is down, and the vapor recovery unit STILL MUST BE ABLE TO RUN, then you SHOULD make it is two separate syetems.

But if the latter can not run or don't have to run without the former, then I would be happier with an integrated system.