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Table 1 EIA RS-485 specifications

From: Optimizing linear routing in the ToLHnet protocol to improve performance over long RS-485 buses

Parameter Conditions Min Max
Driver output voltage Open circuit ±1.5 V ±6 V
Driver output voltage R L=54 Ω ±1.5 V ±6 V
Driver output short-circuit current Output at 12 V or −7 V   ±250 mA
Driver output rise time R L=54 Ω, C L=50 pF   30 % of bit width
Driver common-mode voltage compliance R L=54 Ω −1 ±3 V
Receiver sensitivity −7 V<V cm<12 V   ±200 mV
Receiver common-mode voltage range   −7 V −12 V
Receiver input resistance   12 kΩ