ID-DCU-MARINE-2.2.2,  ©ComAp – June 2015   - 138 - 
ID-DCU-MARINE-2.2.2.pdf 
ID-RPU functions 
ID-RPU (InteliDrive Redundant Protection Unit) is designed for marine applications. This no microprocessor 
unit provides redundant engine protection, RPM measuring and back-up power supply switching for the 
control system.  
ID-RPU monitors InteliDrive central unit and in the case of fail switches itself to the backup mode or 
Emergency backup mode and protects the engine using its own binary EMERGENCY STOP and SHUT 
DOWN inputs and FUEL and STOP SOLENOID outputs.  
 
The ID-RPU unit has three operational modes: 
  Normal 
ID-DCU MARINE is working and periodically sends the watchdog impulses to the ID-RPU. All ID-RPU 
inputs and outputs are processed via ID-DCU MARINE. 
  Backup 
ID-RPU unit doesn’t receive watchdog impulses from the ID-DCU MARINE. The Shut down (Sd1 to 
Sd5), Emergency stop inputs (fix 0,5 sec delay) and Overspeed protection are processed via RPU only. 
ID-RPU stays in the mode that was before ID-DCU MARINE fail. 
  Emergency backup 
ID-DCU MARINE was in EME mode (or Sd override function was active) before fail. The only Emergency 
stop and Overspeed protection is active in this mode. Shut down Sd1 to Sd5 inputs are inactive. ID-RPU 
starts to Emergency backup mode after power on without active ID-DCU MARINE. 
 
 
 
 
 
Power supply terminals A+, A-, B+, B-, COM+, COM- 
The ID-RPU module has two independent power input terminals and one power output terminals. The power 
output is supplied from battery A and if this voltage drops under 8V, the relay switches to the power supply 
B. 
Battery B is switched to A when: Batt A > 10VDC and Fault reset button is pressed on ID-DCU MARINE or 
Batt reset button is pressed on ID-RPU when ID-DCU MARINE is out of order. The voltage switching levels 
is fix set in the ID-RPU. 
 
Hint: 
Short supply drop out occurs during battery A to B or B to A switching. Connect B terminals in parallel to A 
when redundant battery B is not used. 
 
Binary inputs SD1 … SD5 – shutdown channels 
Include broken wire detection. The input logic is Normally Opened. Inputs are NOT active if controller unit is 
in EME mode or Sd override is active. No LED indication. 
 
Hint: 
There is no I/O state or Broken wire LED indication on ID-RPU module. All indications are visible on ID-DCU 
MARINE screen include Alarm list and History record. 
 
Binary input Emergency stop 
No Broken wire detection. The input logic is Normally Closed. Input is active in all EME, AUX and PRP 
modes. No LED indication.