On 18/10/11 12:21, Bob Goodwin wrote:
On 18/10/11 12:00, Brian Mury wrote:
> On Tue, 2011-10-18 at 11:36 -0400, Bob Goodwin wrote:
>> How do I determine if I have the right serial port
>> permissions, where do I look?
> The serial port device should be owned by root, and belong to the
> dialout group, with both the owner and the group having read and write
> permissions. You can verify this like this:
>
>> ll /dev/ttyS*
> crw-rw---- 1 root dialout 4, 64 Oct 18 01:21 /dev/ttyS0
> crw-rw---- 1 root dialout 4, 65 Oct 18 00:28 /dev/ttyS1
> crw-rw---- 1 root dialout 4, 66 Oct 18 00:28 /dev/ttyS2
> crw-rw---- 1 root dialout 4, 67 Oct 18 00:28 /dev/ttyS3
> crw-rw---- 1 root dialout 4, 68 Oct 18 01:14 /dev/ttyS4
> crw-rw---- 1 root dialout 4, 69 Oct 18 00:29 /dev/ttyS5
> crw-rw---- 1 root dialout 4, 70 Oct 18 01:28 /dev/ttyS6
> crw-rw---- 1 root dialout 4, 71 Oct 18 01:10 /dev/ttyS7
>
> Yeah, I've got a lot of serial ports! :-)
> The column that says "root" is the owner.
> The column that says "dialout" is the group.
> The second and third characters are the owner read/write permissions (r
> or w indicates permission, - indicates no permission).
> The fifth and sixth characters are the group read/write permissions.
>
> You can run "system-config-users" as root, and add your user account to
> the dialout group. You'll need to log that user out and back in after
> making that change.
>
> Brian
>
>
This is what I see there and it looks ok to me:
[bobg@box9 ~]$ ll -al /dev/ttyS*
crw-rw----. 1 root dialout 4, 64 Oct 18 03:14 /dev/ttyS0
crw-rw----. 1 root dialout 4, 65 Oct 18 03:14 /dev/ttyS1
crw-rw----. 1 root dialout 4, 66 Oct 18 03:14 /dev/ttyS2
crw-rw----. 1 root dialout 4, 67 Oct 18 03:14 /dev/ttyS3
I haven't changed anything in "system-config-users" I've set up
on a second F-15 computer and still can't see anything toggle on
DTR or RTS. Perhaps my test method is invalid? I am simply
looking at the voltage between signal ground and those two
points at the end of a cable with no termination, it is always a
high negative value, above 12 volts.
Bob
Ok I've added "dialout" but still don't see a change in
voltage,
on the second computer it sits at -11+? I logged out/in, perhaps
a reboot is required? I'll try that.
Bob