Rockwell Factorytalk and DH+ issues

I am changing some HMIs from RSView32 to Factorytalk. I am also adding 5 new HMIs. This has resulted in 17 nodes on a DH+ highway with 7 of those nodes SLC 504s. The highway is set at 115K baud rate. I am having issues with the screen data disappearing and reappearing. Also some loss of data transfer. Very slow to update as well. My question is, is this too much data for a DH+ highway. I have the option of changing the existing PLCs to 505 and use ethernet but this will be expensive. All the processors need to message data between them so I cannot split up the highway. Anyone else experience these type of issues? Using RSLINX Classic with max packets set at 4 for all topics.

Depending on the messaging going on between processors, you may have a network that is taxed and HMI's could stall it. You could change the screen updates to a slower frequency and the SLC messages may also be slowed down without any impact but you would know better. Also, consider a network analyzer:
http://www.ab.com/db/encompass/bps_dir_update.show_page?x_directory_id=2732&x_region=AMERICAS

Instead of swapping out all of the processors for 5/05s, I would consider looking into Controllogix rack, processor, DH+/RIO module, and Ethernet module acting as a data concentrator. Leave the SLCs on DH+ (for now) but add a message instruction to each that would update "their" reserved memory block in the concentrator. The HMIs would be on ethernet and could interact thru the concentrator. 99%+ of the HMI traffic is for viewing anyways, why bog down that DH+ network with it.

Just a thought