
Service Operations and Testing
Testing the Indicator
VT200/220 Technical Manual, Rev 1.00.01
74
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TM-VT200/220-EN
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 units are 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:
30
–
SCALE
32
–
TARE
33
–
P.TARE
34
–
35 –
TOTAL
37
-
PCS
8.2.3
Testing Digital Input and Outputs (Function 93)
To test digital input and outputs (setpoints):
1. Access the function menu and select function 93.
2. The display shows the status of the inputs and outputs, as follows:
The first digit from the left displays data received on the digital input
channel.
The fifth digit from the left displays data sent on output 1.
The sixth digit from the left displays data on output 2.
3. Press
TOTAL
(
) to toggle output 1 on and off. When it is on, the data sent should
be displayed in the fifth digit. If the output connects to another device, check if the
signal was received.