Frequently Asked Questions - All FAQs
The SPNConference has a powerful new echo canceller that can handle echo cancellation for multiple incoming signals from the far side. You can have multiple codecs and a phone line coming in and bridge all of them together. You will need to assign a minimum of four signal buses (or mixes) for conferencing. We suggest the following protocol. Setting up the AEC signal routing. Conferencing requires a minimum of four mixes. Two are dedicated to the AEC itself. These are called the AEC Reference mix and the AEC Signal mix. You will need to assign two mix buses in the ASPEN units for these two mixes. We recommend you use mix bus 48 for the AEC Reference and Mix bus 47 for the AEC Signal. The third is the SEND Mix (AEC Out) – you will need to assign a bus for each outbound signal. For example – if you have just a telephone line, you will need one SEND mix for the Tel. If you have one phone and two Codecs, then you will need three Send mixes, one for the telephone and one for each of the codecs. We recommend you use the mix buses 46, 45, 44 etc for these signal mixes.
This will keep all your conferencing mixes close together and separate from your local amplification mixes. Finally, you will need your LOCAL mixes – these are the signals which will be sent to your local amplifiers and may be shared with microphones. How many of these you need is dependent on the number of amplifier channels you have in use. Reference Mix – should carry ONLY the incoming signals from the far side. That would be signals from the telephone, and codecs – the inbound part of any two way communications line. DO NOT put any microphones or local line level sources (such as multimedia inputs) on this mix. AEC Signal mix – should have ONLY the local microphones. No multi-media sources, no line level inputs – microphones only. AEC Out Mix(es) – Will SEND the output of the AEC (which is the echo cancelled microphones), plus any multi-media sources to the fars side. If you want to have a bridged conference system, you will have the codec incoming going to the telephone SEND mix and the telephone going to the codec SEND mix. BE CAREFUL HERE! Make certain that you do not accidentally route the incoming telephone signal BACK on the outgoing telephone SEND mix! Or Codec to codec, etc! Local Mixes – this brings the audio from the far sides and the microphones into the room – note that we are routing the incoming phone and codec signals to the same buses as the local microphones which then feed to the amplifiers.
Currently, there is not a LecNet 2 version of the TH3A. You can, however, interface the TH3A with the DM series but you must reserve one audio input and one audio output on the DM. Use the AUX IN and AUX OUT ports on the TH3A tied to an audio output and audio input respectively on the DM mixer.
The TH4 (LecNet 2) is in development and will interface with the DM series mixers via the Digital interface. It will not require an audio input or output from the DM mixers to connect.
ASPEN latency is 1.33ms for the SPN812 and 1.43ms for the SPN1624. As you stack additional units, you add only 125 microseconds per additional link (two RU units have 250 microseconds). The 1GB backbone upon which ASPEN Net runs keeps latency extremely low. 125 microseconds is equal to a mere 6 audio samples.
Yes, the protocol for controlling the Venue wireless is easy to use and we are developing modules you can include in your programming. You can adjust levels, change frequencies, change operating modes (such as type of diversity), check transmitter battery levels and many other functions. You are not limited to just these two control systems. Because we have transport neutral protocol, there are many ways (including HTML pages) to control LecNet 2 devices.
Contact our control systems specialist, Frank Gonzales for assistance.
ASPEN is self organizing. You won't do anything. Once your rack is built and the units interconnected with the single Cat6E cable, the ASPEN units will organize themselves into the correct Master/Slave configuration automatically. The top unit will become the master and all the subsequent units will be slaves. If you add another unit to the stack, it will be added automatically in about 90 seconds. Because the 48 mix buses are bidirectional, whatever assignment you have made for the output mixes will remain correct regardless of position n the rack.
The only effect the sequence will have in your rack will be on the control side. You can control an entire multi-unit ASPEN system through a single RS232 port but it MUST be the RS232 on the Master unit. Commands to the slaves will be preceded with a numerical designator surrounded by square brackets so the stack of ASPEN units will know which command is for which unit. Example : run(3) will run macro number 3 in the second unit in the rack. So, the position of the unit will be important when writing control code.
The AM series (also called LecNet) used a communications protocol developed before the dominance of third party control systems. Primarily intended for our software to control AM16/12, AM8, DSP4/4 etc, it was a hexidecimal programming code designed for use by computer programmers. The PT3 is a protocol translator that can easily convert AMX commands into a string of LecNet commands. Up to 92 AMX commands, (pulse, level, or channel) can be associated wih a LecNet command or string. The PT3 is not required, it is simply a programming aid designed to make AMX code writing easier. You CAN control with AMX directly but the code will be more complex. The PT3 cannot help with Crestron systems. The PT3 is NOT needed for the DM LecNet 2 series products.
It is surprisingly hard to do. The big problem is the battery terminal voltage is heavily influenced by how the battery has been discharged in the past. If it has been run down slowly with power gradually pulled out say over a 24 hour period, the relationship between remaining battery capacity and terminal voltage is fairly well defined. If the battery has been discharged heavily, say by a Lectro UM250, the relationship is not so clear. Basically the battery bounces back to a high voltage and can look like it is still pretty fresh. Under either a light or heavy load it will run down quite rapidly. The problem is, the battery tester has no way of knowing the past history of that particular battery.
As a demonstration, if a fresh 9 Volt is accidentally shorted out with a piece of metal for 1 minute, you will get very odd results. The battery will get moderately warm. If the battery then sits unused for 8 hours, the terminal voltage will then measure pretty close to a new battery even under a brief load, but it will only run a transmitter for 5 minutes or so and then die almost instantly. In fact, if you then let it sit for a while again, the voltage will come back up again and die again in a transmitter in just a few minutes. I agree that this is an extreme case but it does demonstrate the problem of prior history.
Even when you know the history you can get bit. Recently we have been running battery tests on different brand batteries and we have found that some alkaline batteries tend to die very rapidly at the end of their life but other brands continue to run with lots of warning before they finally die. What's worse, different batteries from the same manufacturer may act differently. The reason we did the test is that we were getting complaints that the UCR201 was not giving sufficient warning with batteries made by XXXX brand, a major manufacturer. We tested the batteries and found that Evereadys gave 34 minutes of operation after the battery indicator started flashing its warning and the XXXX brand were giving about 3 (!) minutes of warning. We found this to be consistent with XXXX from 3 different parts of the country. Since so many of our dealers sell XXXX, we aren't sure what to do other than recommend Eveready as the standard. The XXXX brand is a perfectly good battery but it has a slightly different chemistry that is optimised for things other than high current drain.
The safest answer is that a low voltage reading will always indicate that a battery is weak but a normal or high reading may not necessarily mean that a battery is good. This is why so many pros that absolutely depend on their equipment, put in a fresh battery at the beginning of a job or whenever there is the slightest doubt that the battery will "last long enough"