Honeywell RK-MCU Product Instructions page 13

No. Parts/Ports
70V interface of
19 external power
amplifier
20 MODE
21 Calibration key
22 DC power output
System extension
23
interface
24 Fan
25 Backup power input
26 Grounding screw
Description
70V audio interface of external power
amplifiers includes CH1B IN, CH2A IN,
CH2B IN and the IN/OUT of spare amplifier.
DIP switch to set the work mode of current
device and system.
To calibrate speaker line impedance.
24V DC power output.
Zone expander connection.
Cooling fan controlled by temperature.
24 VDC backup power supply connection.
Note: This function is not applied in North
America.
Grounding wire connection.
11