Tadiran Telecom Coral IPx 800 Series Installation Procedure And Hardware Reference Manual page 301

The IPx 500X expansion cage includes two 50-pin connections: the top connection is
female; the bottom connection is male. The top female connection connects the first
expansion cage to the second expansion cage. The lower male connection connects
either to the female connection on the main cage or to the female connection on the
first expansion cage.
H719 Power Supply Duplication Cable
H719 cables supply power from cages that house a PS19 DC-D power supply unit to
other cages (Figure 6-53). This cable is supplied with the PS19 DC-D power supply unit
at specific customer request and is connected between the P1 connector of any two
IPx 800 cages in one of the following situations:
When one PS19 DC-D power supply unit supplies two IPx 800 cages with power.
The H719 cable supplies the second cage with power.
When two PS19 DC-D power supply units supply two cages with power. In this
case the H719 cable is connected to provide redundancy if one PS19 DC-D unit
fails.
For further information, see
between Two Cages.
page 7-28, Connecting the Power Supply Duplication Cable
6-61
Cage Description