Panasonic KX-TD500 System Reference Manual page 127

Cable Pin Numbers to be connected (E&M Line)
• E&M Line Wiring
50-pin
Block Terminal
Connector
26
1
27
2
28
3
29
4
30
5
31
6
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
11 11
12 12
Bridging Clips
2-C-49
E&M Line 1