- 36 - Handheld Ultrasonic Flowmeter
6.7The M command and the ASCII Codes
The protocol provides the capability of virtual key-pressing. A remote RS-232C terminal can send
an ‘M’ command along with a key code to simulate the scenario that the key is pressed through the
keypad of the flowmeter. This functionality allows the user to operate the flowmeter in the office
far away from the testing site.
For example, the command “M1” is sent to the flowmeter through the RS-232C link, the flowmeter
will treat the command as if the user has pressed the 1 key through the keypad.
The ASCII codes and corresponding key values of the keypad keys are listed in the following table.
Key
Hexadecimal
Key code
Decimal
Key code
ASCII
Code
Key
Hexadecimal
Key code
Decimal
Key code
ASCII
Code
0
30H
48
0
8
38H
56
8
1
31H
49
1
9
39H
57
9
2
32H
50
2
.
3AH
58
:
3
33H
51
3
◄
3BH,0BH 59
;
4
34H
52
4
MENU
3CH,0CH 60
<
5
35H
53
5 ENT
3DH,0DH 61
=
6
36H
54
6
▲
/+
3EH
62
>
7
37H
55
7
▼
/-
3FH
63
?
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