Exposition (and an example of why we always ask for the exact PanelView part number):
Code:
2711 PanelView Standard
K Keypad
3 3" LCD Screen
A Monochrome. Originally meant "Amber".
2 Data Highway 485 with DH485 modular plugs (not RS-232, no printer port)
L1 DC 24V power
If this is connected to an SLC-5/03, it's very probably going to use the dedicated-purpose Data Highway 485 cable from the "AMP jack" on the PanelView to the RJ-45 network jack (DH485) on the SLC-5/03 CPU.
Those came in a handful of premade lengths, and 1747-C20 is twenty feet long.
RA didn't make longer pre-made cables for that specific connection because the PanelView's isolated network port actually gets 24V DC power through that cable from the SLC-5/03's network port, so the voltage drop through those small conductors limits you to about 20 feet.
If you used separately-powered network isolators like the 1747-AIC or the 1761-NET-AIC, you could run the full 4000 feet or so of trunk cable length supported by DH485 network signals.