Specifications

Appendix C - Cabling Considerations Loop Current vs Cable Length
206
Mediatrix 4100
Loop Current vs Cable Length
When installing the Mediatrix 4100, be sure that the cable length is not too long for the loop current.
Considering the following operating parameters:
 Standard analog devices such as telephones or faxes with typically 300 Ohms of DC
impedance.
 Cable with 85 Ohms/Km (AWG26)
 0 dBm signal at interface
Observe the following values:
Rdc max includes both equipment (standard analog telephones or faxes) and cable DC resistance. This is
illustrated in Figure 37 on page 206
.
Figure 37: Max DC Resistance
Table 135: Max DC Resistance
Loop Current
in mA
Maximum Cable
Length in Meters
Rdc Max in
Ohms
20 2100 660
25 1000 470
30 450 375
32 300 350