Welch Allyn Micro Tymp 2, Руководство по обслуживанию

Страница: 44 / 66

2. How to Determine the Error
Each error register can be assigned any one of the 256 possible hex numbers listed above. Each
number represents a specific combination of errors. By converting the HEX number in the error
register to its binary equivalent and using the error code tables below, you will be able to determine
what errors caused the unit to display the NEEDS CAL message. Notice that the binary numbers
actually contain eight individual numbers that are either 0 or 1. These eight numbers correspond to
the eight blocks of each table. A zero for any particular block in the table means that error didn’t
occur. A one means an error did occur. For example, lets assume the Historical Slave Error Register
($AC) contains a $08. The first thing to do is to convert the $08 to binary. Looking up in the table
we see that $08 = 00001000 in the binary column. Matching the binary digits with the Historical
Slave Error Register Table, we see that the 1 is fourth from the right which corresponds to a Home
Pump Error. More than one error can be indicated by either or both of the error registers. For
example, assume the Historical Master Error Register contains a $0a. The binary equivalent is
00001010. Notice now that there are two digits that are set to “one”. Matching this binary number
with the Historical Master Error Table we see that a Pressure Transducer Error occurred and so did
a Slave Error. Multiple errors are not that common. Most of the time you get a NEEDS CAL message
you will find only one error indicated by the error registers. The N/A blocks in each table indicate
that these locations aren’t used for errors. If you ever determine that one of these locations contains
a one, then you can assume the associated microcontroller has been damaged and no longer functions
properly.
Historical Slave Error Register - $AC
ROM RAM A/D I2C Bus Home N/A N/A N/A
Error Error Timeout Error Pump
Error Error
Historical Master Error Register - $AD
N/A N/A N/A N/A Pressure EEPROM Slave RAM
Transducer Checksum Error Error
Error Error
Once you have determined what error was responsible for causing the NEEDS CAL to be dis-
played, you must determine why. This is done by looking up the particular error in the following
section. Possible causes will be listed next to the error in addition to suggestions of areas to
further investigate.