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FAQs



The following are Frequently Asked Questions received directly from customers. This list is added to frequently.


Q: How to daisy-chain a TTL/Balanced signal from one D/I Mux to another D/I Mux.
Q: What to do if there is no dial tone through an FXS card.
Q: The internal ring generator on a D/I Mux III power supply is not ringing the telephones connected through an FXS card.
Q: How do I generate a sealing current on an E&M card?
Q: How do I bring an 8KHz TTL timing signal into the D/I MUX III?
Q: How do I set up a back-to-back E&M Tandem circuit?
Q: How do I terminal into the D/I Mux III?
Q: My SDCU card keeps going into loopback on its own.
Q: I need help with mapping.
Q: What do I need to know before I call Coastcom's technical support with a problem?

 

QUESTION: How do I daisy-chain TTL/Balanced signals from one D/I Mux to another D/I Mux?

ANSWER:  Daisy-chaining the D/I MUX III clocks is a great way to derive a common timing source while only using one port off of a clock generation device.

Run the Balanced clock into D/I MUX A on the DB-9 connector labeled "Sync I/O" (located on the back of the chassis to the right-hand side):

Pin 1 (EXT SYNC balanced -)
Pin 8 (EXT SYNC +)

Diagram:
Balanced Clock 8kHz--->D/I MUX III A--->D/I MUX III B

To daisy-chain the clock simply connect pins:

DIMUX A     DIMUX B
-----------    -------------
Pin 2      to  Pin 1
Pin 7      to  Pin 8

Be sure on each chassis to provision via software that timing will come in off of the local DB-9 Sync I/O connector. Use commands "SC"
(set to internal) and "SS" (set to Local DB-9).

Note: the D/I MUX III is looking for a square wave at 8kHz to 1.544mHz in multiples of 1600khz. Please note also that the DB-9 Sync I/O clock does
not accept a composite or bits timed clock.

 

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QUESTION: I installed an FXS card in the D/I Mux III and cannot get dial-tone on my phone. What do I need to check?

ANSWER:  

Here is a list of things to check:
 
1. Verify the FXS port has been mapped to the proper timeslot on the T1. Too often the dial-tone provider and end-user do not establish this critical info prior to installation. Use the "SM" command to edit the timeslot assignment map. Use the "DM" command to display the timeslot map. Verify also that the map you have edited for FXS is the active map. Use the command "DN" to display the working map.
 
2. Take the phone off-hook. Whistle into the telephone, do you hear side-tone? Sidetone is the little bit of audio of yourself talking that you hear in the receiver of your phone. Doing this will verify the presence of talk battery (DC -48 current).
 
If the phone is completely dead then:
 
A. Verify that you are using the correct pairs. Consult Coastcom FXS documentation for pair assignments.
 
B. Verify that you have a working telephone (connect to another analog line elsewhere).
 
C. Verify that the D/I MUX III is powered up and that the alarm log does not display any power related alarms.
 
D. Verify that the T1 is not alarming. If you mapped the FXS port to the T1-1 direction then check the alarm log (issue the "DA" command) and verify that there are no active T1-1 related alarms (no Red Alarms, Loss of Framing, Yellow Alarms, etc.).
 
E. Verify that the Talk Battery jumper, labeled "TB", on the back of the chassis (colored blue) is strapped to the "In" position. On the 8 slot chassis the jumper is positioned behind a transparent plastic guard plate. You will need a phillips screwdriver to remove the plate.
    
3. Verify the A-B bits being received and transmitted. A-B bits are used to convey from one end to the other the state of each telephone line. For example, using loop-start signaling if a phone is on-hook then the transmit A-B bit pattern is "01", if the phone is off-hook then the transmit A-B bit pattern transmitted is "11". Monitoring the A-B bits is a great way of seeing what the T1 "sees" for hook-status.
 
The A-B bits can be monitored by using the "OL" command. For example if the FXS card is in slot 5 then you would type "OL 5". From that point select option "5) Report signalling bits status".
 
Use this command in conjunction with the FXS signalling state tables (found in Coastcom FXS card documentation) so that you can
interpret what the A-B bits indicate.
 
Since the output from the command is just a snap-shot of the A-B bits you will need to run the command over and over to get a better view of what is occurring. A good test though is for you to take your telephone off-hook
and verify that the proper A-B bits are being transmitted to the T1 network.
 
Also, look at what the remote end is sending to you. Check the Receive A-B bits. Is the receive a steady pattern, e.g. "01" indicating idle, or are you getting junk bits? Junk bits are random violations that do not pertain to a valid A-B bit pattern. If junk then you will  see, for example, "10" "01", "11", "01" even  though there is not a status change on the remote  end (no one has gone off-hook and placed a call, etc.)
 
4. Verify that all DACS in between the switch and the FXS card have the cross-connects done properly. All cross-connects must be provisioned for Voice signalling (as opposed to a data cross-connect). DACS vendors all have varied terminology to describe voice cross-connects. Examples are VSIG, VOICE, Robbed-Bit. 
 

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QUESTION: How do I daisy-chain TTL/Balanced signals from one D/I Mux to another D/I Mux?

ANSWER:  Daisy-chaining the D/I MUX III clocks is a great way to derive a common timing source while only using one port off of a clock generation device.

Run the Balanced clock into D/I MUX A on the DB-9 connector labeled "Sync I/O" (located on the back of the chassis to the right-hand side):

Pin 1 (EXT SYNC balanced -)
Pin 8 (EXT SYNC +)

Diagram:
Balanced Clock 8kHz--->D/I MUX III A--->D/I MUX III B

To daisy-chain the clock simply connect pins:

DIMUX A     DIMUX B
-----------    -------------
Pin 2      to  Pin 1
Pin 7      to  Pin 8

Be sure on each chassis to provision via software that timing will come in off of the local DB-9 Sync I/O connector. Use commands "SC"
(set to internal) and "SS" (set to Local DB-9).

Note: the D/I MUX III is looking for a square wave at 8kHz to 1.544mHz in multiples of 1600khz. Please note also that the DB-9 Sync I/O clock does
not accept a composite or bits timed clock.

 

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QUESTION: I installed an FXS card in the D/I Mux III and cannot get dial-tone on my phone. What do I need to check?

ANSWER:  

Here is a list of things to check:
 
1. Verify the FXS port has been mapped to the proper timeslot on the T1. Too often the dial-tone provider and end-user do not establish this critical info prior to installation. Use the "SM" command to edit the timeslot assignment map. Use the "DM" command to display the timeslot map. Verify also that the map you have edited for FXS is the active map. Use the command "DN" to display the working map.
 
2. Take the phone off-hook. Whistle into the telephone, do you hear side-tone? Sidetone is the little bit of audio of yourself talking that you hear in the receiver of your phone. Doing this will verify the presence of talk battery (DC -48 current).
 
If the phone is completely dead then:
 
A. Verify that you are using the correct pairs. Consult Coastcom FXS documentation for pair assignments.
 
B. Verify that you have a working telephone (connect to another analog line elsewhere).
 
C. Verify that the D/I MUX III is powered up and that the alarm log does not display any power related alarms.
 
D. Verify that the T1 is not alarming. If you mapped the FXS port to the T1-1 direction then check the alarm log (issue the "DA" command) and verify that there are no active T1-1 related alarms (no Red Alarms, Loss of Framing, Yellow Alarms, etc.).
 
E. Verify that the Talk Battery jumper, labeled "TB", on the back of the chassis (colored blue) is strapped to the "In" position. On the 8 slot chassis the jumper is positioned behind a transparent plastic guard plate. You will need a phillips screwdriver to remove the plate.
    
3. Verify the A-B bits being received and transmitted. A-B bits are used to convey from one end to the other the state of each telephone line. For example, using loop-start signaling if a phone is on-hook then the transmit A-B bit pattern is "01", if the phone is off-hook then the transmit A-B bit pattern transmitted is "11". Monitoring the A-B bits is a great way of seeing what the T1 "sees" for hook-status.
 
The A-B bits can be monitored by using the "OL" command. For example if the FXS card is in slot 5 then you would type "OL 5". From that point select option "5) Report signalling bits status".
 
Use this command in conjunction with the FXS signalling state tables (found in Coastcom FXS card documentation) so that you can
interpret what the A-B bits indicate.
 
Since the output from the command is just a snap-shot of the A-B bits you will need to run the command over and over to get a better view of what is occurring. A good test though is for you to take your telephone off-hook
and verify that the proper A-B bits are being transmitted to the T1 network.
 
Also, look at what the remote end is sending to you. Check the Receive A-B bits. Is the receive a steady pattern, e.g. "01" indicating idle, or are you getting junk bits? Junk bits are random violations that do not pertain to a valid A-B bit pattern. If junk then you will  see, for example, "10" "01", "11", "01" even  though there is not a status change on the remote  end (no one has gone off-hook and placed a call, etc.)
 
4. Verify that all DACS in between the switch and the FXS card have the cross-connects done properly. All cross-connects must be provisioned for Voice signalling (as opposed to a data cross-connect). DACS vendors all have varied terminology to describe voice cross-connects. Examples are VSIG, VOICE, Robbed-Bit. 
 

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QUESTION: The internal ring generator on the D/I Mux III power supply (p/n 30315-105) is not causing the telephones connected locally to the FXS card to ring. What might be wrong?

ANSWER: 

Verify that the jumper W3 on the power supply card is set to "I" (Internal), Not "O" (Out) which is for external ring generation. The jumper is located near the backplane connector on the power supply. Remember to remove any live power source before removing the power card. Out of the factory the W3 jumper is always set to Internal. But on many occasions within the customer network a power supply may be moved from one site to another. At the prior site external ring generator was being used and at the new site internal ring generator is being used.

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QUESTION: I need to generate a sealing current on an E&M card (p/n 33245-107) on my 12-slot D/I Mux III but am not having any luck. What might be wrong?

ANSWER:  There are two things to check. First, on the chassis locate the "TB Strap" and verify that the jumper is set to "In". Second, verify that on terminal connector TB1 (found on the back of the chassis) that Battery Pin 1 labeled "1 BATT" is strapped to Talk Battery Pin 3 labeled "3 TB". This is not how it is shipped from the factory so you will need to run a strap between Pin 1 and Pin 3. 

Important note: all wiring must be performed with the power source disconnected.

After performing these steps for sealing current on the E&M pairs (from T to T1 or R to R1 -- no sealing current is on the E or M lead) use a voltmeter (set for DC milli-Amps) to look for DC current at 12 to 23 mA. The most common mistake made when measuring sealing current is putting the voltmeter on T to R, or T1 to R1 (you will not see the 12 to 23 mA).

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QUESTION: How do I bring an 8KHz TTL timing signal into the D/I Mux?

ANSWER:  First locate the Synch I/O port on the back of the D/I MUX III.

It is located to the left of the RS-232 Control Port. You can bring

in the +3 Volt TTL signal in on Pin 8. Also run Ground on

Pin 2. Please note that a true TTL signal does not swing negative

- it is always positive polarity.

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QUESTION: How do I set up a back-to-back E&M tandem circuit?

ANSWER:  E&M tandem is an application where two E&M ports are back-to-back in the same chassis. This requires 2 E&M cards since different E&M signaling types need to be provisioned via jumpers (there are no software settings for E&M signaling types).

Network design:

  • Switch/FXO-T1-----D/I Mux III w/ 2 4W E&M Deluxe cards--------FXS channel bank

  • This requires 2 E&M cards in the same chassis

  • Must use two cards to run tandem since two different signaling types must be provisioned

Card A setup:

  • Provision a card for PLR (jumpers) and FXS loop-start

  • This card must face the FXS!

  • PLR must be matched with FXS loop-start

Card B setup:

  • Provision the other card for either E&M Type I or III (jumpers) and FXO loop-start

  • This card must face the FXO!

  • E&M Type I or III card must be matched up with FXO loop-start


 

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QUESTION: How do I terminal into the D/I Mux III?

ANSWER: If you're connecting directly to the "CONTROL PORT," make sure to use an operational straight-through cable.

Also make sure you're connected to the correct com port on your computer. Next, check the terminal settings.

Terminal settings should be set at:

"Data bits" 8
"Parity" NO
"Stop bits" 1
"Terminal emulation" VT100 or ANSI
"Baud rate." If you are unsure of the baud rate, start at 1200 (the factory setting) and cycle up to 19.2.

NOTE: If using hyperterminal, you must disconnect and reconnect after each change.

Troubleshooting tip:
If the CCU doesn't respond immediately, hit the ENTER or RETURN key a number of times rapidly to "wake up" the CCU. This situation typically occurs if the CCU hasn't been accessed recently.

If still unable to communicate with the CCU, it is possible that a complete power cycle will restore communications. Make sure to schedule down time, a power cycle will interupt service.
 

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QUESTION: My SDCU card keeps going into loopback on its own.

ANSWER: Modules affected: All revisions of the 30351-101, -101, -102, -103, -104, -105 SDCU's and the 30451-101 Dual SDCU.

It has been noted on occasions that the SDCU cards will revert to looping/un-looping during normal operation. This is apparently more prevalent when interfacing routers. The end result to the customer is the appearance of the data circuit going up and down for no reason, slow traffic conditions caused by router retransmissions, file transfer failures, or corrupted files. Occasionally, but not always, you can catch the card in remote loop via an 'OL' or 'DD' inquiry.

The cause for this anomaly is the routers HDLC, PPP, etc. types of encapsulation framing, and certain software applications, can emulate the SDCU's remote loop up and down codes. Frame Relay applications, utilizing our SDCU cards, can also be affected.

This situation can be easily remedied by setting the cards Hardware switch (located on the front panel) to the #1 position. Do not push the enter button. Then, in the D/I Mux'es software under the 'OL' screen, set the card for Normal/Ignore Loop Codes (#1) then quit. That is it.
 

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QUESTION: I need help with mapping.

ANSWER: Mapping usually follows shelf configuration. The appropriate command to begin mapping is "SM Edit." You will again be asked a series of questions. Choose your working map (1-7) and in which direction you would like to edit. In drop-and-insert and dual-channel-bank modes you'll have the options of T1-1 or T1-2, in channel-bank mode you'll have the T1-1 option. Next choose "Linecard assignment map." If you're creating a new map, choose "Y" when asked to clear linecard map. If you're editing a map on an existing system, choose "N." From there you simply assign time slots to the appropriate card.

Select the "Line Card Slot Number" for the first card.
Choose which DS0 or DS0s you want to assign to that particular card.
If you want to continue editing, answer "Y" until you are finished.
When you are finished editing/creating, answer "N" when asked to "Edit More?"
Answer "Y" to apply changes.

NOTE: It is recommended that you do not edit the working map while your system is running. Instead, use the "CM Copy" command to copy the map into an empty map, edit the copied map, then use the "SN Set Working" command to change your working map to the new map. You will not experience any interruption in traffic during this operation.

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QUESTION: What do I need to know before I call Coastcom's technical support with a problem?

ANSWER: Make sure you know all applicable information about your system, including:

timing source
all other equipment involved (PBX, DACS, routers etc.), including product names, part numbers and specifications
description of your application
problem details
carrier name.

To expedite a solution to your problem, have a modem available to dial into the D/I Mux III. If this is not possible, it may be necessary to have technicians at the site(s) with a terminal connection to the D/I Mux III so they can communicate with Coastcom technicians and make the recommended changes and tests. Access to a fax machine is also recommended. While
on-site, be sure to bring any available test equipment and ANY AVAILABLE SPARES FOR TROUBLESHOOTING.

We recommend you make an appointment for help with configuring your D/I Mux III.

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