AT&T 75 Wiring Manual page 204

Z100-TYPE HARDWARE
PDM, Trunk Data Module, or 212-Type Modem Switch Settings
PDM or Trunk Data Module
The following switch settings are recommended:
212-Type Modem
The following switch settings are recommended:
2-178
Switch
SELF TEST
LOC LOOP/REM LOOP
1 2 0 0
AANS (PDM Only)
SIGLS
PRTY
1/0D
All Others
Switch Setting
A L OFF
S T OFF
R D L OFF
D L OFF
H S ON
Setting
OFF
OFF
ON
ON
ON
ON
ON
OFF