> >> > > I was following a discussion on this list about the > >>TDM400P > >> > revisions. > >> > >It is my understanding that the current revision that > >>one > >> > should have > >> > >is the Rev. H and not the E/F. I have not yet been > >>able to > >> > verify the > >> > >rev stamped on the board, but zaptel is reporting > >>that I > >> > have the Rev. > >> > >E/F. I just bought this card in January direct from > >>Digium and was > >> > >wondering if I got the wrong Rev. > >> > >somehow?? I have been having some intermittent > >>problems but only > >> > >thought it was my setup. > >> > > > >> > >> > >> > >> I did some more testing today. I called Digium on 4/12 > >>and they > >> suggested some things to try, like different > >>motherboard, switching pci > >> slots, etc.. I did everything they asked, except for the > >>mother switch > >> as I do not have a different one to put in the system at > >>this time. > >> > >> So, after all that, my ringing issue still persists. Too > >>some > >> measurements from bot the card and my POTS line in both > >>the on-hook > >> state and ringing state. I uses a digital multi-meter to > >>make the > >> measurements on both. Here are the results.... > >> > >> TDM400P > >> > >> Before slot change: > >> > >> On hook idle: > >> > >> 43.8 Volts DC > >> 0 Volts AC > >> > >> Ringing: > >> > >> 0 Volts DC > >> 56.4 Volts AC > >> > >> After slot change: > >> > >> On hook idle: > >> > >> 48.7 Volts DC > >> 0 Volts AC > >> > >> Ringing: > >> > >> 0 Volts DC > >> 65.5 Volts AC > > > > We can only assume the above represents a fxs module on > >the > > card. Correct? > > > > I would find it hard to believe that changing slots > >would cause > > the on hook DC voltage to change from 43v to 48v. That > >smells like > > a funcky voltmeter. Slots should have nothing to do with > >DC > > voltage unless the module is simply bad. The AC > >(ringing) voltage > > is reasonable, but again it should not have changed > >simply > > because of a slot change; again, questionable voltmeter. > > > >> On my POTS line: > >> > >> On hook idle: > >> > >> 43.8 Volts DC > >> .013 Volts AC > >> > >> Ringing: > >> > >> 50.5 Volts DC > >> 93.9 Volts AC > > > > The on hook DC voltage from all US telco's will > >factually be > > in the 48v to 52v range. If their central office > >equipment produced > > 43 volts, they would have alarms going off all over the > >place. > > Their alarms would trigger somewhere in the 46 to 48 > >volt range. > > So, that measurement implies the voltmeter is not > >accurate. > > The AC (ringing) voltage is well within acceptable telco > >limits > > and can range from about 70v to upwards of 105v. > > > >> Could it bee that from the phone company they retain the > >>DC offset > >> voltage while applying a ring frequency and as it > >>appears on the TDM it > >> shuts off the DC offset when ringing starts. Could this > >>be the issue > >> with those of us in the U.S. having ringing issues with > >>the TDM's?? > > > > Doubtful that is an issue. The reason for saying that is > >the chipset > > used on the fxo & fxs modules was manufactured by > >Silicon Labs, and > > those same chipsets are used in other telephony > >equipment worldwide. > > Silicon Labs is known for good to excellent products. If > >their chipsets > > didn't function correctly, there would have been a large > >uprising a > > couple of years ago when those chips were first > >produced. That > > hasn't happened, and they don't have a lengthy chip > >revision history. > > > > Asterisk code does not have any control over > >adding/removing the DC > > component during ringing, so that's not an issue either. > >Doubtful > > that adding/removal the DC component would have any > >impact on > > normal telephone sets, however there certainly could be > >funcky sets > > that don't like that DC removal. > > > > Given the number of postings relative to the TDM card > >lately, I don't > > remember exactly what your ringing issue was. Could you > >remind us > > without deleting the significant parts of the above? > > > > > > Even though it is long, I will leave everything intact. > > I have had a few issues with dropped calls when using the > FXS to FXO connection. Not sure what the issue is with > that. THe main issue I have is with the ringing on the FXS > card. I have three differnt brands of phones and all three > do the same thing. I might get two or three calls in where > everything works fine. But then the next one will cause > intermittent ringing one all phones and no data for caller > id. > > I have tried every combination of the phones I have that > is possible. From only one of each type hooked directly to > the FXS card to hooking the card to my internal house > wiring and using various combos of the phones connected. > > It almost acts like the phones are requiring just a hair > more ring voltage to work properly. That is why I was > testing the voltage levels. I will try and grab a > different meter to test with.
There is a compile-time option to increase the ring voltage. I don't recall the specifics, but its likely in wctdm.c or an associated header file. (As you probably can tell, I don't use the fxs modules on my TDM card.) > The system is a PIII 933MHZ, VIA chipset and has a 500 > watt power supply in it. So I don not think it is a power > issue from the computer itself. That shouldn't be a problem at all. > The reason I asked about the DC offset during ringing, is > that on the telco side, I noticed that the offset remained > even when ringing voltage was applied. On the TDM, it does > not. In the manual for the chipset that someone sent me, > there is the option to apply a DC offset voltage during > ringing. Additionally, the telco side gives the 93 Volts > AC when ringing where the TDM is only supplying the 65 AC > as according to my meter. These tests were conducted > several times to get average readings. I think you can safely assume that Mark (and/or digium) tested the fxs modules with at least a couple of phones, so its unlikely there is a software issue such as the offset parameter lurking. > As far as the issue with DC voltage on the POTS line only > being 43.8 DC, my guess was that is just an issue with > voltage drop on the line because of distance between me > and the CO. No possible way. If everything is truly on hook, there isn't any current draw and therefore no way for a voltage drop to occur. Basic ohm's law. > If I need to answer anything else, please let me know. > > > P.S. - I do realize that that the chipset is a good > shipset. I am just wondering if everything is setup > correctly in the zaptel driver for the proper programming > of the registers in the chipset to make it function within > specs. I don't know about the fxs module, but I know for a fact that the fxo module has more capability then what has been implemented in the current driver. _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
