@beaglebone:~$ show-pins | grep relay
P9.42                             89 fast rx      7 gpio 0.07        relay-cape (relay-cape)
P9.30                            102 fast rx down 7 gpio 3.16 lo >>  relay-jp3 (relay-cape)
P9.42                            104 fast rx down 7 gpio 3.18 lo >>  relay-jp2 (relay-cape)
P9.27                            105 fast rx down 7 gpio 3.19 lo >>  relay-jp4 (relay-cape)
P9.41                            106 fast rx down 7 gpio 3.20 lo >>  relay-jp1 (relay-cape)
P9.41 / jtag emu3                109 fast rx      7 gpio 0.20        relay-cape (relay-cape)

@beaglebone:~$ ls -ld /dev/gpio/relay-*
lrwxrwxrwx 1 root root 23 Mar 19 00:22 /dev/gpio/relay-jp1 -> /sys/class/gpio/gpio116/
lrwxrwxrwx 1 root root 23 Mar 19 00:22 /dev/gpio/relay-jp2 -> /sys/class/gpio/gpio114/
lrwxrwxrwx 1 root root 23 Mar 19 00:22 /dev/gpio/relay-jp3 -> /sys/class/gpio/gpio112/
lrwxrwxrwx 1 root root 23 Mar 19 00:22 /dev/gpio/relay-jp4 -> /sys/class/gpio/gpio115/