 |
 |
 |
 |
|
|
|
The VDRM100 module mounts in one position of a type 10 shelf. The module plugs into a 56 pin connector at the rear of the shelf.
The VDRM100 is powered by any filtered voltage between -22 and -56vdc. Current is 20 to 30ma.
All connections to the VDRM100 are made on the 56-pin card edge connector.
| DESIGNATION | PIN | DESIGNATION | PIN |
| Tip | 47 | Relay common 2 | 34 |
| Ring | 49 | Relay normally open 2 | 32 |
| L1 audio tip | 37 | Relay normally closed 2 | 36 |
| L2 audio ring | 39 | Answer | 23 |
| Relay common 1 | 11 | Lock ground | 15 |
| Relay normally open 1 | 9 | Power; negative | 35 |
| Relay normally closed 1 | 13 | Ground; positive | 17 |
The VDRM100 has a 3-position dip switch that must be set before the module is put into service.
| SWITCH S1 | OPEN | CLOSED |
| 1: IMPEDANCE | BRIDGED >10k ohms |
TERMINATED 600 ohms |
| 2: SENSITIVITY | LOW -45dB to -22dB |
HIGH -25dB to 0dB |
| 3: MODE | VOX MODE | ANSWER MODE |
S1-1 is used to select either 600 ohm or bridging input impedance to the module in the Vox mode. Set S1 closed for 600 ohm termination. Set S1 open for a bridging connection. In the bridging connection verify that the facility was preciously terminated.
S1-2 is used to select the input sensitivity range for operation in the Vox mode. Set S2 open for a detection threshold from -45 to -22dbm. Set S2 closed for a threshold range from -25 to 0dbm. Adjustment within either range is made via front panel R15 threshold control.
S1-3 is used to set the operating mode. Set S3 open if speech energy detection is to be used to operate the relay (Vox mode). Set S3 closed for the answer mode.
In the answer mode, the module's speech detecting circuitry is disabled and the relay operates when an external ground signal is received. The answer mode is selected when S1-3 is closed. The relay operates when there is a ground to the LG lead and a momentary ground, 50ms or longer, appears on the Answer lead. The relay remains operated until ground is removed from the LG lead.
Voice activation is selected when switch 3 is open. In the voice activated mode, the VDRM100 speech detection threshold is continuously adjustable over two switch selectable ranges: -45 to -22dbm and -25 to 0dbm. A second front panel control provides adjustment of the relay release delay. This delay is adjustable from approximately 400ms to approximately 6 seconds. These adjustments provide a means for discriminating against background noise that may contaminate the input speech signal and for preventing release of the relay during momentary pause in speech.
In the Vox mode, the VDRM100 input impedance may be set to terminate or bridge the circuit. With S1-1 closed, the circuit is terminated. When terminated, the module's input impedance is 600 ohms. When bridged, the module's input impedance is in excess of 10,000 ohms. The VDRM100 can therefore be used either to terminate a transmission facility or to function in a bridging capacity across a circuit terminated elsewhere.
Alignment of the VDRM100 for voice activated operation consists of setting the sensitivity threshold and hangover time controls located on the module's front panel. No alignment of the VDRM100 is required in answer mode application.
To adjust the sensitivity threshold, first make sure that S1-2 is set for the appropriate sensitivity threshold range. Next, turn the threshold control fully clockwise. The control is now set for minimum sensitivity. Using a transmission measuring set connected to pins 47 and 49 insert 1khz tone at the desired threshold level. Close S1-1 to provide the proper 600 termination for the test set. Adjust the threshold control slowly counter clockwise until the relay just operates.
To adjust the hangover time, turn the hangover time control fully clockwise for maximum hangover time. Remove the input test tone. Note the amount of time before the relay de-energizes. Turn the hangover time control counter clockwise as required to shorten hangover time to the desired duration.
|
|
|