NEC ASPILA EX Feature Manual page 168

Operation
154 Features
To make a Step Call:
You step through Extension Groups set in Program 16-02.
1. Place call to busy Department Group member.
OR
Place call to Department Group pilot number.
2. Press Step Call key (PGM 15-07 or SC 851: 36).
3. Repeat step 2 to call other Department Group members.
Department Step Calling
Aspila EX Software Manual