TD-23LV replaces TD-23, see phased out modems below. Please note the new DIP-switch setting and extended AC-/DC supply.TD-23 LV is designed for dedicated lines on 2- or 4- copper cable using the V.23 standard. Multidrop a......TD-23LV replaces TD-23, see phased out modems below. Please note the new DIP-switch setting and extended AC-/DC supply.TD-23 LV is designed for dedicated lines on 2- or 4- copper cable using the V.23 standard. Multidrop and point-to point configurations are possible up to 1 200 bit/s and maximum bus length on 25 km.Multidrop: The recommendation is to terminate the receiver on the master unit and the final bus slave unit.