address@hidden:~]$ ldattach 18 /dev/ttyS0
address@hidden:~]$ ldattach 18 /dev/ttyPS0

address@hidden:~]$ ls -l /dev/pp*
crw------- 1 root root 108, 0 Jan 12 19:06 /dev/ppp
crw------- 1 root root 243, 0 Jan 14 11:10 /dev/pps0
crw------- 1 root root 243, 1 Jan 14 11:10 /dev/pps1

address@hidden:~]$ ppscheck /dev/ttyS0
# Seconds  nanoSecs   Signals
1547464400 999138515
1547464401 024727403 TIOCM_CD TIOCM_DSR
1547464401 999126037
1547464402 024727632 TIOCM_CD TIOCM_DSR
1547464402 999121309
1547464403 024720460 TIOCM_CD TIOCM_DSR
^C

address@hidden:~]$ ppswatch /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
timestamp: 1547464335, sequence: 107, offset: -901986
timestamp: 1547464335, sequence: 107, offset: -901986
timestamp: 1547464336, sequence: 108, offset: -902298
timestamp: 1547464336, sequence: 108, offset: -902298
timestamp: 1547464337, sequence: 109, offset: -902640
timestamp: 1547464337, sequence: 109, offset: -902640
timestamp: 1547464338, sequence: 110, offset: -902961
timestamp: 1547464338, sequence: 110, offset: -902961
timestamp: 1547464339, sequence: 111, offset: -902539
timestamp: 1547464339, sequence: 111, offset: -902539
timestamp: 1547464340, sequence: 112, offset: -902901
timestamp: 1547464340, sequence: 112, offset: -902901
^C

address@hidden:~]$ ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1547464239.024701287, sequence: 11 - clear  1547464239.999111405, sequence: 12
source 0 - assert 1547464240.024703074, sequence: 12 - clear  1547464239.999111405, sequence: 12
source 0 - assert 1547464240.024703074, sequence: 12 - clear  1547464240.999101199, sequence: 13
source 0 - assert 1547464241.024711266, sequence: 13 - clear  1547464240.999101199, sequence: 13
source 0 - assert 1547464241.024711266, sequence: 13 - clear  1547464241.999100756, sequence: 14
source 0 - assert 1547464242.024702508, sequence: 14 - clear  1547464241.999100756, sequence: 14
source 0 - assert 1547464242.024702508, sequence: 14 - clear  1547464242.999103039, sequence: 15
source 0 - assert 1547464243.024702501, sequence: 15 - clear  1547464242.999103039, sequence: 15
source 0 - assert 1547464243.024702501, sequence: 15 - clear  1547464243.999101077, sequence: 16
source 0 - assert 1547464244.024702805, sequence: 16 - clear  1547464243.999101077, sequence: 16
^C

address@hidden:~]$ ppscheck /dev/ttyPS0
# Seconds  nanoSecs   Signals
1547464540 999126149
1547464541 024715359 TIOCM_CD TIOCM_DSR
1547464541 999114721
1547464542 024715723 TIOCM_CD TIOCM_DSR
1547464542 999113992
1547464543 024713864 TIOCM_CD TIOCM_DSR
^C

address@hidden:~]$ ppswatch /dev/pps1
trying PPS source "/dev/pps1"
found PPS source "/dev/pps1"
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
^C

address@hidden:~]$ ppstest /dev/pps1
trying PPS source "/dev/pps1"
found PPS source "/dev/pps1"
ok, found 1 source(s), now start fetching data...
time_pps_fetch() error -1 (Connection timed out)
^C