Main monitoring unit
From uCtrl.net
 |  I am moving to a new location, and therefor terminating the Rack box project, my plan is to build an even bigger system based on slot-in cards in a full size rack. I'll keep you posted. Feel tree to leave a comment if you have any question. |
Contents |
Information
This unit monitors all necessities in the Rack box. It gives an alarm if a power supply should fail, a fuse burn out or if Serial Server times out (via. OSID). 5, 12 and 24V, positive and negative, is connected to optoisolators inside the MMU. The 24V uses en external optoisolator. It will detect if a main fuse burns out or a power supply is lost. MMU is bypassed the main fuses, but if the 12V supply is totally lost MMU will also lose power. Fuse errors is detected by the fuse module FB1, and the signal sent to MMU which gives an alarm and notifies other modules. Serial Server monitoring is based on the same principles that MSMU2 operates on, a lifesignal is sent ever X second. And if this signal fails to come a timeout alarm will sound. The lifesignal from Serial Server is only sent every 60 seconds, and it takes 310 for the timeout alarm to sound. OSID is the serial module delivering the lifesignal, so if this module fails this will be detected as a server timeout.
I/O
Inputs
- Server lifesignal
- Fuse error
- Emergency supply failure (see EMG)
- 5V supply
- 12V supply
Outputs
- Buzzer (not in use)
- Error signal (to SLCU)
- Fuse error LED
- Supply failure LED
- Lifelight (built-in LED)
- Lifesignal (to MSMU2)
- Server timeout LED
Wires
- Yellow 12V+
- Blue 0V
- Black Server lifesignal (in)
- Red Fuse error (in)
- Purple Emergency supply failure (in)
- Green 5V+ supply (to optoisolator)
- White 5V- supply (to optoisolator)
- Orange 12V+ supply (to optoisolator)
- Brown 12V- supply (to optoisolator)
- Green Buzzer (out)
- Yellow Error signal (out)
- Orange Fuse error (out)
- Grey Supply failure (out)
- Brown Lifesignal (out)
- Cyan Server timeout (out)
Alarm situations
- Server timeout (310 sec)
- Emergency supply failure
- 5V supply failure
- 12V supply failure
- Fuse error
Images
 Assembly |
 Assembly |
 Complete |
 Installed in the Rack box |
 Additional PCB |
 Testing using SIM6IO |
 Program flow chart |
MMU installed in the Rack box |
Schematic drawing
Source code
The program is written in basic, using Bascom-AVR.
'-------------------------------------------------------------- ' Thomas Jensen '-------------------------------------------------------------- ' file: AVR_MMU ' date: 12/03/2006 '-------------------------------------------------------------- $crystal = 4000000 $baud = 9600 Config Portd = Input Config Portb = Output Config Watchdog = 1024 Dim Feil As Integer Dim Feil_prev As Integer Dim Timeout As Integer Dim Horn As Integer Dim Nettspenning As Integer Dim Lifesignal As Integer Timeout = 3100 Lifesignal = 31 Portb = 0 Portb.2 = 1 Waitms 1000 Portb.3 = 1 Waitms 1000 Portb.6 = 1 Waitms 1000 Portb.4 = 1 Waitms 1000 Start Watchdog Portb = 0 Main: If Pind.3 = 0 Then 'emergency supply NC Feil = 1 Nettspenning = 1 Waitms 100 End If If Pind.5 = 1 Then '12V supply NO Feil = 1 Portb.3 = 1 Waitms 100 Portb.3 = 0 End If If Pind.4 = 1 Then '5V supply NO Feil = 1 Portb.3 = 1 Waitms 100 Portb.3 = 0 End If If Pind.2 = 0 Then 'fuse failure Feil = 1 Portb.2 = 1 Waitms 100 Portb.2 = 0 End If If Pind.0 = 0 And Timeout = 0 Then 'set timeout timer Timeout = 3100 End If If Timeout > 0 Then Timeout = Timeout - 1 'timeout timer If Timeout = 0 Then Feil = 1 Portb.6 = 1 Waitms 100 Portb.6 = 0 End If If Pind.0 = 0 Then Timeout = 3100 If Horn > 0 Then Horn = Horn - 1 'horn If Horn = 6 Then Portb.0 = 1 If Horn = 1 Then Portb.0 = 0 If Feil = 1 And Feil_prev = 0 Then Horn = 10 'failure output signal If Feil = 1 Then Portb.1 = 1 Feil_prev = 1 If Timeout > 0 Then Timeout = Timeout - 1 End If If Feil = 0 Then Portb.1 = 0 Feil_prev = 0 End If If Nettspenning = 1 Then Portb.3 = 1 'emergency supply set If Nettspenning = 0 Then Portb.3 = 0 Feil = 0 Nettspenning = 0 If Lifesignal > 0 Then Lifesignal = Lifesignal - 1 'lifesignal If Lifesignal = 6 Then Portb.5 = 1 If Lifesignal = 1 Then Portb.5 = 0 If Lifesignal = 0 Then Lifesignal = 31 Reset Watchdog 'loop cycle Portb.4 = 1 Waitms 25 Portb.4 = 0 Waitms 75 Goto Main End
