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FDO 3000 Off-Net Order-wire

FDO 300 Off-Net

Summary of Features

  • Interfaces telephone network to DTMF selective signaling order-wire network
  • Privacy, all call and conferencing features
  • Single rack-unit housing with space for digital interface card in expansion slot
  • Two-wire and four-wire versions available
  • Companion order-wire unit available
  • Save long-distance charges by using order-wire network for calls via a local POTS line
  • Call in or call out between order-wire network and the public switched telephone network


The FDO 3000 Off-Net interfaces the FDO 1000-series order-wires to the public switched telephone network (PSTN) via 2 wire or 4 wire line. Microprocessor control of the FDO 3000 brings maintenance communications into the 21st century.

DTMF Selective Signaling
The FDO Off-Net uses its on-board microprocessor to synthesize and decode DTMF signaling tones. The Off-Net can be programmed for automatic privacy, manual privacy, no privacy and hoot-n-holler modes.

Companion Order-Wire
The FDO 3000 Off-Net is normally installed adjacent to an FDO 1000 Order-Wire terminal. In VF network applications, the off-net interfaces the order-wire network either directly or through the 4-way passive bridge on the order-wire. If the off-net is used in a digital network, its voice signal is converted to digital by an Adaptive PCM (ADPCM) card in the order-wire housing.

Digital Interface
The FDO 3000 Off-Net can be equipped with a DVF-64 digital interface card in the expansion card slot. This interfaces a 24 Kbit port to the ADPCM card in the order-wire. The DVF-64 also provides an 8 Kbit port for digital alarm data and a 32 Kbit port for or analog alarm data.

LED Indicators
Front panel LEDs indicate order-wire off-hook, incoming call ringing and channel busy. Front panel test points and level controls allow calibration while the unit is in place.

The Off-Net responds to one, two or three digit addressing. Leading zeroes in the address will set it for one or two digits. Rotary switches on the P.C. Board allow the address to be easily set. The station address is posted on the front panel with stick-on labels (labels are included).

Network Control
In privacy modes, the FDO 3000 generates DTMF tones to control access to the order-wire network. When an off-net caller calls the off-net while the order-wire network is in the busy state, he will hear a busy signal. If he calls while the network is un-busy, he hears dial. tone and an off-hook tone is generated to the order-wire network. This causes other stations on the network to assume a busy state. If any order-wire station phone is picked up during the busy state, a busy signal will sound in the earpiece. Stations that are busied remain in that state until their station code is dialed from the caller's phone or until the caller hangs up, generating an on-hook tone.

Order-wire stations call the off-net by dialing a one, two or three digit code, like any other station. The off-net seizes the PSTN line and returns dial tone from the central office or PBX. The caller then dials an off-net number as though he were using a regular phone. Upon completion of the call, the off-net sends an on-hook tone to the order-wire to reset the busy state.

Conferences on an order-wire allow participation by an unlimited number of parties. Anyone at an order-wire station can add additional stations to a conference by dialing *, # and the station code. An off-net station can be included, but it must be the last station added to the conference.

Application Packages
The FDO 3000 is available in application packages that include KDA alarm network elements and the FDO 1000 Order-wire. Contact DPS inside sales for details.


Order-wire application
Applications: FDO 1000 Order-Wire and FDO 3000 Off-Net can operate on VF or digital network.


2-Wire Return Loss: >40 dB
2-Wire Trans-Hybrid Loss: >38 dB
Frequency Range: 300 to 3000 Hz
Physical Size: 1-3/4" X 19" X 12" case
Weight: 3 lbs
Voltage Range: Option 0 = -18 to -72 VDC
Option 2 = -18 to -36 VDC
Option 4 = -36 to -72 VDC
Current: 200 mA
Fuse: 1 Amp
Order-wire channel: -26 to -3 dBM
Off-net Port, 4-wire: -26 to -3 dBM Transmit
-26 to -3 dBM Receive
Off-net Port, 2-wire: -9 dBM
FCC Part 68: The off-net uses a commercially produced coupler circuit that is part 68 approved.
FCC Reg. number: 2FKusa-73217-VP-N
Connector: RJ-11c connector
Ringer equiv: 0.0B

Additional Options and Part Numbers

  • FDO-3000-10A-V0: FDO 3000 Off-Net Order-Wire Interface
  • FDO-1000-10A-0V: Companion Order-Wire - VF Order-Wire (w/o phone)
  • FDO-1200-10A-00: External speaker with level control, mounts on wall or rack side rail
  • FDO-1301-10A-00: Trifling Phone w/DTMF Dial, 4-wire, beige
  • FDO-1301-10A-01: Trifling Phone w/DTMF Dial, 4-wire, white
  • FDO-1501-10A-00: Active 4-way/4-wire Bridge
  • D-PG-410-11C-04: Terminal Order-Wire with Off-Net. Includes Order-Wire and ADPCM Card; phone, speaker, off-net and DVF-64 card (2 housings)