The FOM-3941 and FOM-3942 both provide complete electrical isolation for Nortel’s Meridian™ M2000 and M3000 series digital telephones. The FOM-3941 connects to the digital line card and automatically senses and corrects any improper polarity reversals on the RJ-11. The bidirectional signaling between the digital line card and telephone is then carried across a duplex fiber optic cable. The FOM-3942 reproduces the digital signaling at the isolated end of the fiber optic link and provides power sufficient to operate M2000 and M3000 series digital telephones.
The module can be used in areas of high electrical noise or in and out of RF shielded enclosures. The module enhances privacy of communications because fiber can not be tapped without being detected and does not radiate any emissions. The fiber optic cable is not susceptible to interference caused by impulse noise, crosstalk, or EMI. The potential problem of creating ground loops or ground offsets is also eliminated because there is no conductive path through the glass fiber for ground.
In addition, fiber optic cable offers much longer transmission distance than traditional telephone line cord wiring. Nortel’s Meridian™ digital telephones are limited to a maximum distance of 1750 feet (458m) from the PBX to the telephone on 24 gauge wire, but multimode and singlemode optics on the module extend the distance to 2km. A typical link consists of an FOM-3941 at the PBX and an FOM-3942 at the telephone with a duplex fiber optic cable between them
- Supports all system features on Nortel’s Meridian™ M2000 and M3000 series digital telephones.
- Supports balanced 2-wire signaling between PBX and digital telephone.
- FOM-3941 provides automatic polarity correction. If the wiring to pins 3 and 4 are reversed, the module will swap the pair internally.
- FOM-3942 supplies ±15VDC @ 50mA to power digital telephones.
| GENERAL SPECIFICATIONS | ||||
|
Min
|
Typ
|
Max
|
||
| Power Requirement | Voltage Range (V) |
20
|
24
|
34
|
| FOM-3941 Supply Current (mA) |
-
|
200
|
-
|
|
| FOM-3942 Supply Current (mA) |
-
|
360
|
-
|
|
| Data Rate | 512 kbps | |||
| Line Encoding | Balanced Differential AMI (Alternate Mark Inversion) | |||
| Receiver Sensitivity | 400 mVpk-pk (-15bB loss) | |||
| Environmental | Storage Temperature (°C) |
-40
|
-
|
85
|
| OperatingTemperature (°C) |
0
|
-
|
50
|
|
| Interface Connector | RJ-11 (x4) | |||
| PHYSICAL SPECIFICATIONS | ||||
|
Length
|
Width
|
Height
|
Weight | |
| Card Dimensions |
11.25 in (286 mm)
|
0.825 in (21 mm)
|
5..25 in (133 mm)
|
10 oz (0.3 kg)
|
| OPTICAL CHARACTERISTICS - All | |||||||
|
Order Suffix
|
Fiber
|
Fiber Type *
|
Max Dist (km)
|
ʎ (nm)
|
Bandwidth Typ (dB)
|
Loss (dB)
|
Connector
|
| T12 |
Multimode
|
OM2
|
1.88
|
850
|
15.5
|
10.14
|
ST
|
| L12 |
Multimode
|
OM2
|
1.88
|
850
|
14.5
|
10.14
|
LC
|
| T5B |
Singlemode
|
OS1, OS2
|
2
|
1310
|
20
|
12.5
|
ST
|
| L5B |
Singlemode
|
OS1, OS2
|
2
|
1310
|
13.5
|
12.5
|
LC
|
| C | SFP Cage with no Optical Module Installed | ||||||
| * Specs obtained assuming fiber is as described in 'Fiber Type' with a 266MB Data Rate | |||||||
| Standalone Operation | |
| SAC-1-AC | Standalone AC Power Supply |
| Chassis Mounting | |
| RMC-5000 | 4U, 19" Rack Mount Chassis. Holds up to 16 FOM Modules |
| PSM-5000 | Spare AC Power Supply for RMC-5000 |
| PSM-5000-D | Spare DC Power Supply for RMC-5000 |
