Hitachi GR2000 - Manual (Page 196)

3.10.2.4 Metal (Coaxial) Cable for Secondary (G.703)
For connection to the Secondary (G.703) interface, a send-and-receive pair of metal
(coaxial) cables are required per port (DSU). Figure 3-93 shows the cable
specifications. Be noted that neither the single cable length nor the total length of the
Pin No. Function (device side) Function (DSU side)
1 Unused Transmit (+) (B)
2 Unused Transmit (-) (b)
3 Transmit (+) (A) Unused
4 Receive (+) (B) Receive (+) (A)
5 Receive (+) (b) Receive (+) (a)
6 Transmit (-) (a) Unused
7 Unused Unused
8 Unused Unused
Note: Because of the cable being a twist pair cable, make pairs of (A) with (a), and (B) with (b) in the
above pin assignment. For other cables than these, there is no need of worrying about the pairing,
either of being connected or unconnected can be accepted.