Is the pulse from the pipe effectively fed directly into the radio ports
and the SyncInjector just monitors it? Or does the SyncInjector
reference the pipe's output and regenerates before output to the radios?
I know the radios don't really care about a lost pulse here and there.
IIRC, it's like 5 seconds before they declare it lost.
If it's not this then I'm completely lost. Just odd that this seems to
be happening on the towers with the longest runs (240-290 feet). But I'm
far from blaming the SyncInjectors and/or SyncPipes.
I really do believe this is some Canopy bug. I have the on-board GPS
disabled on most of them that are exhibiting this issue. The last time,
I went in and turned them back on and the on-board pulse was
flip-flopping every second or two just like the power port. Cambium
can't reproduce it yet as far as I know. And this really seemed to start
happening when we got AutoSync. I've even seen this happen on single
sectors with their own parasitic pipe as well (no power port timing, and
with the on-board enabled and disabled). So I'm not sure if the on-board
is causing this, but you'd think if it was disabled, then it should not
be possible, but disabling it doesn't actually turn the receiver off.
And like I said, it seems to happen around sundown which tells me it's
either a temperature thing or a GPS Rx issue, plus all of the on-board
receivers are aimed at the horizon through tower steel. And I have other
receivers on the same sites to time FSK radios and they don't have any
problems, just timing ports from deluxe's and parasitics, no other
SyncInjectors though.
I set up a cron script on an NTPd sync'd server to poll the 'used
pulses' counter every hour and output it to a file. We'll see what that
says.
On 11/10/2015 12:38 AM, Forrest Christian (List Account) wrote:
This problem isn't likely to affect all of the radios randomly at the
same time. Since each port is driven by a separate set of
electronics, and you have a separate cable to each radio, any effect
should be radio-specific.
I just looked at the syncinjector firmware - it needs 3-4 lost pulses
before it declares the sync to be lost. I'm planning on tightening
this up a bit to better catch errors like these, but I've got a couple
of other critical items I'm working on before I can get there.
Have you by chance looked at the increments of the sync pulses through
a 24 hour period? In exactly 24 hours, there should be exactly
86,400 sync pulses used - no more no less. If you compare this to a
atomic-synced clock you should be able to get fairly accurate
counts. I.e. read that counter exactly at the top of an hour, and
then look exactly 24 hours later. Be aware of non-accurate clocks
though - my computer drifts a few seconds a day, if I don't sync it
regularly (like a couple of times an hour).
-forrest
On Mon, Nov 9, 2015 at 4:58 PM, George Skorup <[email protected]
<mailto:[email protected]>> wrote:
OK, now I'm very interested. I have multiple sites with regular
10/100 SyncInjectors with 450 APs on them (no need for GigE).
They're all on 200 feet or more cable. Randomly, all APs at a site
will show loss of power port sync. More often, they say the sync
pulse is flip flopping on and off. Sometimes a reboot or a
power-cycle will fix it, but mostly just have to wait a few
minutes for it to clear. This seems to happen right around sundown
most times. I was thinking that the on-board GPS starts freaking
out and triggers some AutoSync bug (which I know exists). I've
pulled out all surge suppressors, swapped SyncInjectors,
SyncPIpes, nothing. And when this happens, the SyncInjector status
says the timing is fine, no events, every time.
But maybe this is actually my problem?? It has been very very rare
on shorter runs (like <150 feet).
On 11/9/2015 5:20 PM, Forrest Christian (List Account) wrote:
Sort of.
First of all, a normal pulse out of a syncinjector into a short
cable:
Inline image 5
Interesting things happen when you shoot this into a long cable:
Inline image 1
Those bounces at the front are my best guess as to what is
causing the 450i to not like the sync pulse. That's on a 100m
cable, and those pulses are most likely caused by the signal
bouncing off the end of the cable and back and/or some different
interaction with a long CAT5 cable. It should be noted that
similar bounces also happen with the 100 and the 450, and even
with official cambium sync sources (aka the CMM Micro), but the
software in those radios seem to ignore the stray pulses, only
paying attention to the final edge. Not so with the 450i. It
just refuses to play.
The new I0 injectors turn the power off a bit more smoothly,
making the bounce not exist, even on a long cable:
Inline image 4
On Mon, Nov 9, 2015 at 4:02 PM, George Skorup <[email protected]
<mailto:[email protected]>> wrote:
Let me guess, they only take a CMM4 aligned pulse?
On 11/9/2015 4:21 PM, Forrest Christian (List Account) wrote:
We have recently become aware of a potential issue when
using a SyncInjector with a PMP450i. The short version of
this issue is that with certain cable runs (mostly longer
ones), a PMP450i will refuse to accept the sync from the
SyncInjector as valid, even though the pulse is perfectly
valid and should be accepted by the PMP450i.
Currently, there are two ways this can be fixed. Since the
pulse is valid, but just not recognized as valid by the
currently shipping PMP450i firmware, Cambium could fix this
in software. I believe they are currently investigating
this as an issue, and I honestly expect them to release a
fix assuming it isn't a major issue to do so. If this
happens, it should address all of the existing SyncInjectors
in the field which our customers may want to use in the
future with a a PMP450i.
The second way to fix this issue is for us to modify our
sync pulse slightly so that it is in line with what the
PMP450i is expecting. Because this modification has some
additional benefits beyond better interoperability with the
current PMP450i firmware (such as the modified pulse being
less likely to induct noise into adjoining cables), we have
decided to proceed down this path as well.
During the next week or so, we will begin shipping Revision
I0 of our Gigabit SyncInjector Product. The first of
these are currently working their way through our assembly
line. This version contains improved support for voltages
above 58V and also the waveform modification mentioned
above. It should be functionally identical to the earlier
Revision H0 SyncInjectors. It is not our intention to
update our non-gigabit injectors at this time.
If you are currently having problems with sync over power on
a Gigabit SyncInjector and a PMP450i, please send an email
into [email protected] <mailto:[email protected]>
and we will work with you to ensure you have hardware which
will work with your hardware.
