DH+ to Ethernet Conversion

I am about to embark on a project to network approx. 150 different PLC skids on to a Ethernet automation network. Our main control system is DeltaV, but all support functions (utilities, equipment washing etc.) are PLC based, mostly AB SLC 5/04s, but some 5/03s, 5/05s, PLC 5s, ControlLogix and Siemens PLCs, with PanelView/PanelView+ and Siemens OP HMIs. There are also some SCADA nodes.



Obviously, the 5/03s and 5/04s cannot connect to Ethernet, so the idea for the 5/04s is to create smaller DH+ networks of grouped equipment, then interface to the Ethernet via a ControlLogix rack with a 1756-DHRIO card and a 1756-ENET card.



First question:

Can a ControlLogix rack be used for just the DHRIO and ENET card or does a controller need to be on the rack?



Second question:

Is a daisy-chain or a tap drop configuration better for this sort of network? Currently, some of the 5/04s are connected to PVs using DH+. Can the PVs be added to the DH+ network?



Third question:
What can I do for the 5/03s?

Fourth question:
Are there any alternatives (apart from swapping all controllers for 5/05s, which would be costly)?

Any suggestions you guys have would be appreciated, as I’m finding the scale of this project a little daunting!

pablo2000 said:

Obviously, the 5/03s and 5/04s cannot connect to Ethernet, so the idea for the 5/04s is to create smaller DH+ networks of grouped equipment, then interface to the Ethernet via a ControlLogix rack with a 1756-DHRIO card and a 1756-ENET card.

Click to expand...

If the DF1 ports are free, you can use the NET-ENI module to get the SLCs onto Ethernet

pablo2000 said:

First question:

Can a ControlLogix rack be used for just the DHRIO and ENET card or does a controller need to be on the rack?

Click to expand...

no need for a controller

pablo2000 said:

Second question:

Is a daisy-chain or a tap drop configuration better for this sort of network? Currently, some of the 5/04s are connected to PVs using DH+. Can the PVs be added to the DH+ network?

Click to expand...

read the manual on DH+ networks, that will give you specs on size of network etc. you will find it on this link http://literature.rockwellautomation.com/idc/groups/public/documents/webassets/browse_results.hcst?familyTitle=Data%20Highway%20Plus%20Network&categoryTitle=Networks%20and%20Communication&xLanguage=EN%20-%20English&CategoryId=0023&FamilyId=0266&PageNumber=1&StartRow=1&EndRow=20&SortField=dDocTitle&SortOrder=Asc&passedLangVal=EN%20-%20English

I have not used a 1756dh485 card yet. This may be an option for you.

Once apun a job or 2 ago I did use a 5/05 as a passthru to a DH485 network. It worked smooth I just added an AIC+ and enabled a few bit in the 5/05 not to bad. This link may help you out also.
http://www.plctalk.net/qanda/showthread.php?t=38046&highlight=pass

Using the 1756-DH485 card in the control logix bridge has not worked well for me.

I can see PanelViews in lin, but cannot upload or download to the panelview. I have 3 PLCs, and 4 PVs on the network, and the comms is SOOOOOOOOO slow. It also slows down the network when I go online with any one of the PLCs.

The DHRIO card seems to work well. It has 4 PLCs, 3 PCs, and 2 PVs on the network, and works great.

I have problems getting RSView Linx Enterprise(for PanelView +) to communicate thru the bridge. Linx Professional, and probably most any other OPC server with the correct drivers should probably communicate thru the bridge fine.