1.  Check the F-89 (System version and build date) 
settings first on all units (see page 108). The two 
parameters O and P (Option Module) must be 
the same on all units before any multiple unit 
connection can be established. 
Example: F-89 O:00, P:01. 
2.  All units must be powered down before starting 
the Multi-Drop mode configuration.