Comtrol RM III V.90 - Manual (Page 3)

Hardware Installation 3
Utilizing V.90 Technology
Utilizing V.90
Technology All V.90 modems are analog line devices. The following figure shows when you can
and cannot achieve 56 Kbps.
• V.90 modems can receive data at rates up to 56 Kbps, provided the data is
being transmitted by a digital modem on a digital (e.g., T1 or ISDN) line.
• V.90 modems can send data over analog (twisted pair) phone lines at a
maximum rate of 33.6 Kbps—even if communicating with other V.90 modems.
• The actual data rate achieved depends on the age and condition of the analog
phone lines, and may be lower than 33.6 Kbps.
Installing the RocketModem III
Use the following procedures to install a single RocketModem III.
European
Installations: Before
Hardware
Installation Before installing this board, ensure that the power drawn by this board, together
with the host and any auxiliary boards drawing power from the host, is within the
rating of the host power supply. Equipment must be installed such that, with the
exception of connections to the host, the clearance and creepage distances shown
in the following table are maintained between the board and other assemblies that
use or generate the voltages shown in the table. The larger distances shown in
(brackets) apply where the local environment within the host is subject to
conductive pollution or dry non-conductive pollution which could become
conductive due to condensation (Pollution Degree 3 environments). Failure to
maintain these minimum distances would invalidate the approval.
Note: Obtain advice from a telecommunications safety engineer for a host or other
expansion boards fitted in the host using or generating voltages greater than
300 V (rms or dc).
Digital
Server
V.90
Server
V.90
User
Telco
Office
Telco
Office
Analog
Telco
Office
Digital Telephone Network
Lines
Digital
Line
56K
33.6K 33.6K
33.6K
Data Data
Rate Rate
Caution
Minimum Clearance Creepage Voltage
2.0 mm 2.4 (3.8) mm Up to 50 Vrms or Vdc
2.6 mm 3.0 (4.8) mm Up to 125 Vrms or Vdc
4.0 mm 5.0 (8.0) mm Up to 250 Vrms or Vdc
4.0 mm 6.4 (10.0) mm Up to 300 Vrms or Vdc