Battery Test; Flash Crc Tests; Sram Test; Communication Port Tests - Daikin MicroTech II Installation And Maintenance Manual

Battery Test

The battery test determines the status of the MCB battery.
When the battery fails the test, the error is indicated by the red
MCB Error LED and the Binary Input BI-1 LED turning ON
during the MCB Error Code Display period. This warning
signals the battery is nearing the end of its useful life and
should be replaced. Regardless of the battery status, the MCB
board continues execution of the on-board program. Once the
Main Control Board LED Power-Up Sequence is complete, if
the battery is bad, the red Error LED blinks on and off at a rate
of one second on and one second off. If the battery is good it
remains off.
Note – After battery replacement, the Error LED will not revert to
the normal off condition until one of the following occurs:
• Power is cycled to MCB
• The battery is tested at two minutes after midnight each
day. If battery is normal then, the Error LED reverts to
normal.

Flash CRC Tests

The startup Flash memory test consists of a sector by sector
CRC check of the following Flash code bases:
• Startup
• Boot
• Main
• Two Flash data bases: Dictionary and Configuration.
The results of all five tests are saved in SRAM for use by the
operating system. A Dictionary failure does not result in a
startup error display. The following scenarios describe the
possible failure modes of the flash CRC tests.
Bad CRC in Startup Code Base.
Flash CRC error during the MCB Error Code Display period,
the startup process continues, if possible. Since the startup
code validity is questionable, correct operation from this point
is unpredictable. Daikin recommends downloading the startup
code again. If this is not possible or ineffective, replace the
MCB.
Bad CRC in Main Code Base and Boot Code Base.
displaying the Main/Boot Flash CRC error during the MCB
Error Code Display period, the startup process continues. After
the startup sequence is completed, execution is passed to the
Boot code. Since the Boot code validity is questionable,
correct operation after entering Boot code is unpredictable. A
CRC failure in only the Boot or only the Main code base will
not result in an error display. Re-downloading the Main and
Boot code is recommended.
Bad CRC in Configuration Data Base.
that requires replacing the MCB. The configuration database
contains user and factory defined configuration parameters
including the device name, communication parameters, and I/
O setup and calibration data. After displaying the
Configuration Flash CRC error during the MCB Error Code
Display period, the startup process continues. If main code is
Daikin IM 696-4
After displaying the Startup
After
This is a fatal error
run, the MCB reboots, resulting in continuously repeating the
error code and reboot cycle. If boot code is run, MCB will run
with factory default values.

SRAM Test

Simply stated, the SRAM test checks each memory location by
writing values to each location, reading the value back and
comparing the read back value to the expected value. If a
SRAM error is detected in the low byte, the RAM Low Byte
failure displays during the MCB Error Code Display period.
The MCB then is reset by an external "watchdog" circuit and
the Main Control Board LED Power-Up Sequence begins
again. If a SRAM failure is detected in the high byte, the RAM
High Byte failure displays and the Serial Bus Port LED turns
ON during the MCB Error Code Display period. The MCB
then is reset by an external "watchdog" circuit and the Main
Control Board LED Power-Up Sequence begins again. If
either the RAM Low Byte or the RAM High Byte error occurs,
replace the MCB.

Communication Port Tests

The various communication ports on the MCB are tested
during the Main Control Board LED Power-Up Sequence.
This feature allows the processor to verify the internal transmit
and receive data paths of MCB data communication channels.
Once in the test mode, proper operation of the various
communication channels is verified by writing data to the
corresponding transmit buffer of the channel under test and
then reading the data back from the receive register. If read
data does not match write data, the MCB displays the
appropriate communication port error during the MCB Error
Code Display period and then continues startup and
initialization. If any of the possible communication port errors
occur, replace the MCB.

IP Register Test

After determining the existence of an optional IP
communication module, the MCB performs a series of read/
write tests on critical registers of the IP processor. If any of the
register tests fail, an IP port failure displays during the MCB
Error Code Display period and then the MCB continues
running startup and initialization. If the IP port error occurs,
replace the IP communication module. If the problem persists
after replacing the IP communication module, it is likely the
MCB is defective. Refer also to the literature shipped with the
IP communication module.
Test Procedures
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