Various ways in which the MD2 modem can be connected to a TIM or other MD2 modems, as well as to the dedicated line (via an LTOP overvoltage protection module), are illustrated below.

Connection of an MD2 to a TIM via the RS232 interface

One MD2 modem can be connected to a TIM via the RS232 interface. This technique can be used to set up "point-to-point" and "line" network configurations as well as a small star network (only with TIM 4) with only two 2-wire lines.

Connection of several MD2s to a TIM via the RS485 interface

Several MD2 modems can be connected to a TIM 4 via the RS485 interface. This type of interconnection is used if a number of dedicated lines have to be combined on a single WAN port on the TIM, i.e. if a star topology is connected, as illustrated schematically below.

Calculating the maximum range (in km) based on transmission rate and wire diameter

The table below can be used to calculate approximate values for the maximum distance in km which can be covered by the MD2 modem, depending on transmission rate and wire diameter.

The values in the table are guide values for non-coil-loaded message lines type 2 x 2 x A J-Y(St)Y (A = core diameter in mm).

A level reserve of 4 dB was applied when calculating the maximum ranges. This should ensure that even in the event of deviations in cable characteristics, which experience has shown to be possible during operation, the level will always be sufficient to ensure fault-free data transmission.

AST = number of tandem stations
1) Not possible on leased telephone lines. Set transmission level to -9 dB.