Home | RTS-2 | RTS-2 Instruction Manual |
RTS-2 FAQ's
1. I cannot access the RTS-2. What should I do?
3. How do I reconfigure for lines 7 & 8 usage?
4. I'm having a hard time reading the "83" chart in section 2.11 (page 30). Any help?
5. My DC power source is above 50 volts -- is this too high?
6. I changed the Test and Program codes, but now only one works.
7. How can I use two RTS-2's to measure bidirectional path loss?
8. What about the lack of profile 2 on v1.4 and later firmware?
9. I can't break dialtone with the "1" command.
1. I cannot access the RTS-2. What should I do?
First, determine the reason. Does it answer the incoming ringing, provide the access prompt tone, and stay connected? (The green light stays on for 15 seconds waiting for a correct Test or Program code.) Try both the Test code and the Program code. Put a * in front of each to flush any incorrect digits received first. If neither works, then the Test and Program codes have been changed, so you must reprogram the unit via direct physical access. See manual section 5.1 to obtain a Program prompt. Program a new Test and Program code according to manual sections 3.4 and 3.5.
Primarily for firmware versions 1.0-1.2: Does the unit hang up as soon as it answers the incoming ring? (The green light comes on for the incoming line and then goes out before you have a chance to enter a Test or Program code.) See manual section 5.3. Additionally, the Central Office (CO) may be momentarily breaking loop current upon answer, causing the RTS-2 to interpret it as a calling party disconnect signal. The solution is to reprogram the Disconnect Time parameter 05. See manual section 3.8.3. A value of 250 milliseconds has been found satisfactory for this situation. See manual section 5.1 to obtain a Program prompt. Program a 250 millisecond Disconnect Time by issuing the command: 9305025. In general, this parameter should be set as small as possible without becoming susceptible to false disconnects. Verify that the unit detects calling party disconnect by calling the unit, entering the Test code, and hanging up on it without issuing the 00 command. If the red loop current LED blinks and the green line light goes out within 30 seconds of hanging up, the setting is satisfactory. If not, try using a lower value than 250 milliseconds which still permits successful answer. If it is not possible to find a value which satisfies both conditons, set the InActivity time to as short a value as possible (manual section 3.8.6) for safety. A setting of 000 disables it (don't do this!); a value of 002 is the lowest which is suggested.
2. The "1" command works fine, but I get an error beep for the 2, 3, and 4 commands. What should I do?
Primarily for firmware versions 1.0-1.2: This will probably only occur if the unit is not configured for ground start lines, and the CO has a brief interruption of loop current upon loop closure. Dial String 234 (which starts at parameter 35) looks for loop current, and aborts if there is none. Replace parameters 35 and 36, which are unnecessary for loop start lines, with two 200 millisecond delays by issuing the commands: 9335133 and 9336133. Remember to enter Program Mode first by logging in with the Program Code.
3. How do I reconfigure for lines 7 & 8 usage?
This will eliminate the Line Monitor and Ground Start line capabilities. Go to Program Mode and enter 9303114 (section 3.8.2, page 36) and change the shorting clips to both right hand figures on page 15 (section 1.8). Also 9311255 (section 3.8.4, page 38) if you want it to answer incoming calls on lines 7 & 8.
4. I'm having a hard time reading the "83" chart in section 2.11 (page 30). Any help?
These measurements are not meant to be more accurate than a decibel. However, you can download this spreadsheet to eliminate squinting at the graph. You can also download this program to do the conversion. Note: it interpolates the above spreadsheet chart to tenth-dB resolution, but that does not alter the underlying precision.
5. My DC power source is above 50 volts -- is this too high?
Yes! It can destroy circuitry. Place a voltage dropping component in series with one of the leads powering J1 or J2. A suitable part is a P6KE6.8CA which drops 6.8 volts (bidirectionally). With it, up to 57 volts is safe. Available from www.Digikey.com, www.Mouser.com, and www.Jameco.com.
6. I changed the Test and Program codes, but now only one works.
Don't make one code the same as the initial digits of the other. For example, if you make the Program Code 12345678 and the Test Code 1234, then you will never be able to get into Program Mode -- because as soon as you enter 1234, Test Mode will be activated.
7. How can I use two RTS-2's to measure bidirectional path loss?
Use RTS-2 unit "A" to call a responder line on RTS-2 unit "B". Issue the ##8 command, disconnect from unit B with ###, and read back the level received at unit A (from B) with the 83 command. Hang up (with 00). Repeat the process using unit B to call unit A to determine the level received at unit B from A.
The above method uses two separate calls, and may be suitable for fixed call setups or for a statistical overview. In order to make bidirectional level measurements during a single call setup, both RTS-2's must have v1.4 firmware or later:
Use unit A to call an access line (not a responder line) on unit B. Log in (to unit B) with the Test Code. Issue the alternate call-in-progress command to B (041). Issue command 71 (to unit B). Issue command ##8 (to unit A) -- it may be necessary to wait for the silent interval for unit A to recognize the command (noted by an immediate silencing). Now unit A has stored the received level from unit B. Send * (to unit B) to get it to exit from its 71 command. Send 82##1: the 82 is to unit B instructing it to measure an incoming signal; the ##1 is to unit A instructing it to transmit a 1000 Hz 0 dBm signal to unit B. After the tone ends, issue the 83 command (to unit B) and determine the level received at unit B from unit A. Send 00 (to unit B) to tell it to hang up. Send ### (to unit A) to end the call to unit B. Send 83 (to unit A) to retrieve the level received at unit A from unit B. Send 00 (to unit A) to tell it to hang up.
The responder line, 71, and ##1 actions nominally generate a 1000 Hz 0 dBm signal. This level is only accurate if the attached telephone line presents a true 600 ohm resistive impedance. Therefore, using the received level as the actual path loss can be incorrect. The readings are best interpreted as relative measurements when compared to previous tests, or compared against similar installations.
8. What about the lack of profile 2 on v1.4 and later firmware?
The +3dB bidirectional path gain provided by profile 002 (section 3.8.8) is often not useful, because unless the network impedances and delay times are very good, some instability will arise. However, when shipped the settings equivalent to that profile are pre-programmed as user defined profile 015. If parameters above 50 have not been altered, it can be employed. To do so, issue command 9324024 (from Program Mode). This needs to be redone anytime the 90173 Initialize All command is given. Subsequently, profile 015 can be used.
9. I can't break dialtone with the "1" command.
The problem is that the attached equipment (cable modem, Central Office, etc.) is not reliably detecting the tones coming from the accessing telephone -- through the access line, the RTS-2, and to the equipment. The default loss through the RTS-2 is 3 dB. It is either a detection sensitivity problem in the end equipment, or the losses in the incoming and outgoing lines are too great for it. Some modern phones only send a short tone burst for dialed digits instead of transmitting the tone pair as long as the button is depressed, and output levels from telephones vary. This problem can be bypassed by talking to the RTS-2 and asking it to dial the number for you. Use the "2" or "3" commands, i.e., to dial 1-616-321-1234 out port 2: access on line 1 and enter the Test Code; enter 32 16163211234#; the RTS-2 will seize line 2 and redial the number with locally generated DTMF signals.