You ask questions backwards.
That is not what I would have guessed.
The best you could do with this hardware is to set up a small DH485 network using using a 1761-NET-AIC module. This would allow you to program the SLC-5/03 and download to the PanelView 600 without disconnecting anything.
If you had a 1784-U2DHP or other DH+ interface to your computer, you could in theory connect to the DH+ network and "pass through" to the DH485 network, allowing you to connect to all three devices without changing cables.
If I had your system, I would buy a general purpose USB/RS232 converter (the Forum favorite is the Keyspan USA-19HS) and dedicate it to the download port of the PanelView 1000 terminal.
You can leave the 1747-UIC driver running to handle the SLC and the PanelView 600 terminal, and use a separate DF1 Full Duplex driver to download to the PanelView 1000.