| Q1
What input voltage is required to operate the
Dual/Quad Modem shelf?
The plug-in power supply provides power for two dual-/quad-modem
shelves (four dual-modem modules maximum).
Input voltage:
-20 V dc to -72 Vdc
Output voltage/current:
o +5 Vdc (4.90 Vdc to 5.20 Vdc) at 1.5 Amps maximum
o +12 Vdc (11.6 Vdc to 12.4 Vdc) at 400 mAmps maximum
o -12 Vdc (-12.4 Vdc to -11.6 Vdc) at 400 mAmps maximum
Power rating:
15 Watts total
Regulation:
o 0.2% line
o 2.0% load
Recommended
external fusing: 2.0 Amps (Type 70) or 2-1/2 Amps (GMT) at -48 Vdc

Q2
What are the external fusing requirements?
Recommended external fusing: 2.0 Amps (Type 70) or 2-1/2 Amps
(GMT) at -48 Vdc

Q3 and Q4
What types of interfaces are available on the
Dual/Quad Modems? AND What are the specifications of the Analog/Digital
Channels?
Digital Serial Channels 1 Through 4
- Protocol:
- TBOS (eight data bits, odd parity, two stop bits)
- TABS (eight data bits, odd parity, one stop bit)
- Speed:
- TBOS (1,200/2,400 bps)
- TABS (1,200 bps)
- Communication type: RS-232, RS-422, or RS-485
- Protection: Sustain transient voltage to a maximum 2 kV
- Connectors: 8-pin Methode connector (Westronic PN 620-0077)
Analog Serial Channels 1 Through 4
- Type: 202T compliant 4-wire
- Speed: 1,200 bps
- Output amplification: +2.0 dBm (maximum)
- Input sensitivity: –6 dBm to –48 dBm (in 6-dBm steps)
- Connection: 3-position D/Level compression plug (Westronic PN
640-0105)

Q5 What
is Rate Adaption?
NOTE: The following applies only to the dual rate-adaption modem
board (PN 532-T009).
With rate adaption enabled, 1,200-bps data on the analog line converts
to 2,400-bps data on the digital side and 2,400-bps data on the
digital side converts to 1,200-bps data on the analog line. Data
converted from 1,200 bps to 2,400 bps has a 10-millisecond delay.
With rate adaption disabled, data rates on the modem analog and
digital sides are 1,200 bps. Data converted from 2,400 bps to 1,200
bps has a 5-millisecond delay.

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