CTC has a Profibus driver called "Profibus L2-DP Slave Driver (DFBS)" that lets your HMI communicate with a Profibus master using Profibus DP protocol. You have to install a communications card in your HMI. They suggest the SS-5136-PFB card from SS-Technologies.
I looked in my version of Interact/DOS and found that the "Profibus DP Slave" drive loaded during the Interact installation on my PC. It also has the following drivers: Siemens HMI Adapter, Siemens RK512, Siemens S5 Programming Port, Siemens S7-PPI, Siemens TI Ethernet, Siemens TIWAY, Simens/Koyo 205/305/405. I checked the InteractX installation and found drivers for Siemens S7 MPI, S5 AS511, S5 S964R, S7-200, S7 Ethernet, Simatic 505 Ethernet, and Simatic 505 Serial Device Driver for TI 500/505. Other than the S7-300/400 stuff, this doesn't mean much to me, but I saw in your first thread, you said you used the TI/Siemens 545 systems, so maybe one of these will help. If you have Interact installed, check if the driver you need is already installed.
CTC used to keep their drivers on their web site, but I can't find them today either. However, not all the drivers are on the web site. Call your distributor or CTC and ask them for the driver if it did not install on your PC when you installed Interact. In addition to the driver, ask for application notes. On one project, I added a DataLogic communications card for a DH+ network and CTC had application notes that really helped.