You need to change the Device Type inside the DF1 Full Duplex driver configuration in RSLinx.
The correct (and often auto-detected) device type will be "SLC-CH0/Micro/PanelView". To browse through a "Pass-Through" connection to DH485 or DH+, the DF1 Full Duplex driver's Device Type needs to be set to "1770-KF3/1747-KE".
The SLC firmware revision at production time is on the sticker on the right side of the CPU, but of course if it's operating or has been upgraded since it was produced, you'll find the firmware revision online in RSLogix 500 in the Status file, under the "Proc" tab.
Using this route of DF1 to DH485 passthrough is a lot of hassle for little gain. If you are trying to upload/download an application you will go further faster by getting your hands on a CompactFlash card in a Type II PCMCIA holder and using that to transfer the application file. Because of the age of these platforms, there are hitches; you need Firmware v3 or better in the PanelView to support "ATA" style memory cards, and usually you need a card of 2 GB or less formatted in FAT16 style.
The Totally Successful No-Fail mechanism to access this PanelView is the USB to DH485 interface, 1747-UIC.