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Quick Reference & Compatibility Guide for the
apt-X™ / 384 System
I. Installation
Your EDnet supplied apt-X / 384 system includes APT's DMS-100 audio codec and Pro-Link ISDN Manager as well as three network termination devices (NT1s). The DMS-100 sits on top of the Pro-Link (rack mounts kits are optional), and the two boxes connect with the 37-pin "IMUX" cable. Note that there are two data connectors on the Pro-Link that accept this cable; the proper one is labeled "DMS-100." Each of your ISDN lines plugs into an NT1 and then into the one of the "S" jacks in the back of the Pro-Link (labeled S1, S2, and S3). The order in which each line plugs into which S-jack is critical. Please refer to your packing list for the correct order, and make certain that the telco jacks in your facility are clearly marked.
II. Pro-Link Specifics
A.) General Configuration Issues
Like all ISDN gear, the Pro-Link terminal adapter requires configuration specific to the attached lines. This includes switch protocol, directory numbers, and SPIDs. If EDnet has provided your telco lines as well as your Pro-Link, then most likely we've taken care of this for you and you're ready to plug and play.
B.) Transmission Modes
(Tip: The transmission mode the Pro-Link terms "Dual Destination" is for mono. If you're doing two separate mono sessions simultaneously, then you're literally in "Dual Dest" mode.)
1.) Mono
Corresponds to the Pro-Link's "Dual Destination" setting. Requires 2 calls (each call refers to an individual ISDN B-channel; each ISDN circuit having 2 B-channels) for 15kHz extension, and 3 calls for full 20Hz-20kHz bandwidth.
2.) Stereo
A minimum of 2 calls is required, yielding 7kHz of top end. A 3rd call yields 12kHz, while a 4th call yields 15kHz. Stereo mode is generally not used with any fewer than 4 calls. To achieve full frequency extension, 6 calls are required. Note that adding a 5th call doesn't extend the frequency response beyond 15kHz
3.) Dual Destination
Uses the same setting as a straight mono session. The Pro-Link, however, will facilitate two separate mono sessions at once. When operating a dual destination session, it's especially important to distinguish between the "left" and "right" sides of the box. The first 3 dialable positions (line 1 B1 & B2; line 2 B1) correspond to the left audio channel; the last 3 dialable positions (line 2 B2; line 3 B1 & B2) correspond to the right audio channel.
(Tip: In Dual Destination mode, the IMUX must be balanced. In other words, if either session is booked as 15kHz [2 calls], then the other session must also operate at 15kHz. Ignore positions 3 & 4 [line 2], putting one session on positions 1 & 2 and the other session on positions 5 & 6.)
C.) Menu Navigation
In idle state, the Pro-Link's display should read "D Channel Active (Ready)" on all six lines (with a 5ESS point-to-point switch there'll be no "Ready" indication). To access the menu tree, hit the "Set" button. The screen will then display six options. Each option is accessed by pressing the appropriate numeral on the keypad. Options 2 ("Set Unit Configuration") and 4 ("Set Line Configuration") will bring you one level deeper, where as options 1,3,5 & 6 set parameters directly. To back out of a given menu level, hit the "Esc" key.
There are two settings within the Pro-Link's menu tree that need to be verified on a session by session basis:
1.) ISDN Line Speed
After hitting "Set" and "4," option 2 will display (on the right hand side in parenthesis) the current line speed. This must match that of APT system you're connecting to. To change to 56k, hit "2" then "5." To change to 64k, hit "2" then "6."
(Tip: At 15k Mono or 15k Stereo you'll only get the full frequency extension displayed on the screen [e.g., "15kHz Mono"] at a 64k line speed. At 56K, roll-off will start just above 13kHz.)
2.) Audio Mode
After hitting "Set" and "2," option 2 will display (on the right hand side in parenthesis) the current audio mode. If the session is mono, it should read "Dual Destination." To change audio modes, hit "2" then use the right arrow key to scroll through the three options. Note that this is also where you put the system into local loopback (not a valid transmission mode, but quite helpful for internal testing). If "Local Loopback" is selected, "20kHz Stereo" will appear on all six lines and the decoder will output what is sent to the encoder. To get out of "Local Loopback," hit the "Esc" key.
D.) Dialing
" key to move the cursor to the next position, then hit "Dial" again. The number you previously entered will appear on the screen. Rather than entering the next number from scratch, you can use the "Del" key to backspace over as many characters of the dialing string as needed. Retype the new number(s), and again hit "Ent." Repeat this process until the proper number of calls have been established. There are two ways to disconnect calls: the "Disc" key will dump all active calls, while the "Del" key will drop only the call that the cursor points to. The Pro-Link is also capable of holding up to 50 speed dial entries. For instructions on setting speed dial configurations, refer to the EDnet manual addendum "How to Set and Use Speed Dial Directory Numbers."
(Tip: If, as the timer is counting down in "Set-Up" mode, it changes to "Waiting" mode, then the call has failed. To get out of "Waiting," hit the "Esc" key and verify that you're dialing the proper number. If the timer reverts immediately to "Waiting" then the call has failed at your end, in which case you may need to reboot [power-cycle] the Pro-Link.)
III. DSM-100 Specifics
A.) Front Panel Controls
1.) Toggle Switches
a.) Digital / Line
Governs which input source (analog or AES / EBU) is active. Both analog and digital outputs are always active.
b.) TC On / TC Off
Controls the time code sub-band, which is multiplexed with the left audio channel and therefore available only in conjunction with the left channel. It has approximately an 11-12 frame delay relative to the audio. In order to use the time code sub-band, both sites must have their TC switches on.
(Tip: If you connect to a remote site and here a loud squeal in the left channel, the remote site may have their TC switch engaged. If you engage yours the noise should disappear.)
c.) AUX
Controls the auxiliary sub-band, which is multiplexed with the right audio channel and therefore available only with the right channel. Both sites should have this switch in the off position unless utilizing this function.
(Tip: If you connect to a remote site and hear a loud squeal in the right channel, the remote site may have their AUX switch engaged. If you engage yours the noise should disappear.)
d.) Normal / Test , SD / DD , Mono / Stereo
These functions are all controlled within the Pro-Link's software and these switches are not functional in this installation.
2.) Rotary Knob
Sets the sampling frequency for the AES / EBU output. Note that the Pro-Link auto-detects a sample rate presented to the AES / EBU input.
B.) LEDs:
Note that certain controls on the DSM's front panel were intended for use with external non-APT terminal adapters and have no function when implemented with the Pro-Link. Only the following LEDs function in this installation:
1.) Individual LEDs
a.) "TX" / "RX"
Indicate whether valid data is being transmitted (TX) and received (RX) by a rapid flash.
(Tip: If the DSM-100 is set to accept a digital input, these lights will only give a rapid flash when signal is present.)
b.) AES / EBU IN & OUT
Display the sampling frequency for the digital inputs and outputs.
c.) Source
Shows which input source has been selected.
d.) Timecode
"Gen" indicates that valid time code from a remote site has been decoded and regenerated; "Read" indicates that valid time code has been input and read by the DSM-100. The TC switch must be engaged for these LEDs to function.
2.) Meters
Although a useful tool, the DSM-100's level meters should not be considered precision instruments. Deflections of between 2/3 and 3/4 are generally appropriate, and a full scale digital signal (e.g., a CD) will light the entire output meter. Note that the input meters function only with the analog input. You'll see no input meter activity when using a digital input source.
C.) Rear Panel
1.) Dip Switches
Most of the dip switches have been replaced by front panel controls, and therefore these switches should virtually never be touched. There are two sets of dip switches. The set of 10, marked "AUX", are factory default right, with only #10 to the left. The set of 4, marked "AES / EBU In" are also factory default right, with only #2 left. If you feed the digital input with a SPDIF bit stream, move this dip switch #2 to the right.
2.) Connectors
a.) Audio
Left and right analog inputs and outputs on balanced connectors; digital input and output also on balanced XLR jacks.
b.) Data
The 37-pin IMUX connector interfaces the DSM-100 with the Pro-Link (and has been discussed in Section I). The 25 pin AUX connector interfaces with both the time code and aux sub-bands. APT includes a "pig-tail" cable, with allows for the input and output of SMPTE via XLR connectors as well as input to the aux channel via a 9-pin serial connector.
IV. Compatibility To Other Codecs
A.) General Compatibility Issues
As discussed in Section IIC, two parameters must be set on a session by session basis. These are "Audio Mode" (stereo or dual destination) and ISDN line speed (56 or 64k). These both must match the settings at the remote site.
B.) Compatibility To Other apt-x Codecs
1.) DSM-100 IMUX
APT manufacturers another version of the DSM-100, one in which the IMUX function (controlled in your system within the Pro-Link) is driven by the DSM-100. This device requires proper configuration of the SD / DD and Mono / Stereo toggle switches. To operate in single destination mode (mono or stereo), the switch must be set to SD.
2.) DRT128
This is the baby brother of your apt-X / 384, and it's fully compatible. A single ISDN line device, it is capable of 15kHz mono.
3.) 3D2
Per a former reseller agreement between APT and Keystone, some APT codecs are marked "3D2," and you'll occasionally hear people refer to their APT systems as "my 3D2." These systems are fully compatible with yours. A common source of confusion stems from the order of the dial-up numbers at 3D2 sites. Where as the Pro-Link offers no flexibility regarding left vs. right audio channels, many 3D2 sites feature 3 or even 6 external terminal adapters. The ports of these TAs can plug into the DSM-100 IMUX unit in any order, and 3D2 chose to make the B1 channels of the 3 respective ISDN lines correspond to the left audio channel and the B2s correspond to the right audio channel. This doesn't present a problem as long as both sites take care to establish the proper dial-up sequence for mono sessions.
C.) Non-APT Codecs
The apt-X 100 coding algorithm is proprietary to APT. Although Comrex implements a version of this algorithm on some of its products, these codecs are still not compatible with your system. If you need to connect to an MPEG device (e.g., Telos and CCSMusicam), a Dolby codec (AC-2 / AC-3 algorithms), or a G.722 unit (e.g., Comrex) then you'll need to arrange use of our EDLink™ bridging service. Call the 800 number that appears below.
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