Service Operations and Testing
Testing the Indicator
VT400 Technical Manual, Rev. A5
58
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#
UM-VT400-EN
To unlock keys:
1. Access the setup menus and navigate to
SETUP
>
SETUP 1
.
2. Set the corresponding parameter to 0 (see the bulleted list above).
8.2 Testing
the
Indicator
8.2.1
Testing ROM/RAM Integrity (Function 86)
From time to time, it is advised to check the integrity of the unit’s ROM and RAM
using the procedure below.
To test ROM/RAM integrity:
1. Access the function menu and select function 86.
2. One of the following messages are displayed:
Err 01
– indicates that ROM data is corrupted.
Err 02
– indicates that RAM data is corrupted.
PASS
– indicates that both ROM and RAM memory is okay.
8.2.2
Testing the Keypad and Display (Function 90, 91)
To test that the display is working properly:
Access the function menu and select function 90. All digits display 0 through 9, in
sequence, and then all characters are displayed in sequence.
To test that the keypad is working properly:
Access the function menu and select function 91. The display blanks. When you
press a key, the scan code for that key is shown on the display. The scan codes
are as follows:
32
–
TARE
.
33
–
P.TARE
.
34
–
.
35
–
TOTAL
.
36
–
FUNCTION
.