He's talking about swapping white/blue with white/brown. So instead of
putting + on one pair and - on the other, you run +/- as twisted pairs just
like the data pairs. So that when the sync pulse suddenly interrupts the
current flow, there is less of an inductive kick and less coupling into the
data pairs. Or so I assume.
-----Original Message-----
From: Jay Weekley via Af
Sent: Sunday, November 23, 2014 11:18 PM
To: [email protected]
Subject: Re: [AFMUG] How common are crc errors on pmp100
How does swapping the blue and brown pairs fix the CRC issue?
Mark Radabaugh via Af wrote:
Are you using Sync over Power on this AP?
There is a known problem with the way that the sync over power works. It
occurs when the cables to the AP are run parallel and tight to steel. If
you tape the cables directly to the tower leg, you will almost always have
a problem with CRC errors.
The power supply wiring for the 430 product fixed the issue, but they went
back to the original wiring in the 450.
A couple of ways to fix the issue:
a) Isolate the cables from the steel using standoffs.
b) Swap one wire each on the blue and brown pairs - Last Mile Gear had a
note on the alternative wiring method at one time. I�m not crazy about
it since it makes for a odd looking connector and the next guy who has to
work on it is likely to cut it off and put it on �right�. The cable
will also fail on any Ethernet tester, making it difficult to convince
anyone that the cable is correct.
c) Turn off Sync over Power and use an alternative sync method - iGPS,
Syncpipe Parasitic, etc.
Mark
On Nov 20, 2014, at 1:24 PM, Bill Prince via Af <[email protected]
<mailto:[email protected]>> wrote:
We don't often see CRC errors on any of our APs, FSK, OFDM, or MIMO.
If you're in lightning territory, check to see if these are coincident
with lightning strikes.
bp
<part-15@SkylineBroadbandService>
On 11/20/2014 9:24 AM, Craig Schmaderer via Af wrote:
This is a radio that has been up for 93 days, it is very heavy on
traffic, would you say there is an issue with this radio? It is on a
clean tower that only I am on. There are 4 other canopy radios on this
tower receiving sync from a CTM1. All radios are just CAT5e cable non
shielded, length is about 180� tops. Also there is a PTP800 with lmr
400 ran along with it, I never noticed this before, all other radios are
showing about the same number of CRC errors, is this expectable?
Ethernet Link Detected :
1
Ethernet Link Lost :
0
Undersized Toss Count :
0
inoctets Count :
4054728244
inucastpkts Count :
1954469296
Innucastpkts Count :
56834740
indiscards Count :
0
inerrors Count :
231695
inunknownprotos Count :
0
outoctets Count :
3150773755
outucastpktsCount :
1289988260
outnucastpkts Count :
1597027
outdiscards Count :
0
outerrors Count :
0
RxBabErr :
0
TxHbErr :
0
EthBusErr :
0
CRCError :
231601
RcvFifoNoBuf :
94
RxOverrun :
0
LateCollision :
0
RetransLimitExp :
0
TxUnderrun :
0
CarSenseLost :
0
No Carrier :
0
/Craig R. Schmaderer/
/CEO | Skywave Wireless, Inc./
/Ph: 402-372-1975 | Fax: 402-372-1058/
/Direct: 402-372-1052/
