32
o. RS-232C interface
Demonstration software is provided with the DMM. The
program is written for windows using MFC. For you own
applications, consult the following;
1. Specification
Baud rate
19200 baud
Parity none
Data length
8 bit
Stop bit
1 bit
2. Transmitte format(DMM to PC)
Output and Input of all data are ASCII String.
Send Format( DMM to PC )
“
fun b sign value b unit b cr lf
”
fun Function(ASCII
code)
b
blank(0x20)
Sign -(0x2E)/
(0x20)
Value
Measured value(ASCII string)
unit
Unit(ASCII string)
cr
Carriage Return
lf
Line Feed
Function code
Function
Function code
Unit
DCmV
DCV
mV
DCV
DCV
V
ACV
ACV
V
Diode
DIO
V
Ohm/Continuity
OHM/BEP
Ohm/ Kohm/ Mohm
Capacitance
CAP
uF/mF
Frequency
FRQ
Hz/ Khz
uA
DCA/ACA
uA
mA
DCA/ACA
mA
A
DCA/ACA
A
Adaptor
AC/DC1,2,3 TMP
A/ tC/ tF
Inductance
IND
mH
31
m. Relative % Mode
The Relative % mode takes the actual reading on the main
display and compares it to a reference value programmed by
the user on the right hand sub-display. The left hand sub-
display will show the percentage the actual reading varies
from the reference value. Activate the function as follows:
1. To use
Relative
% mode manually select the range for
the function.
2. Depress the
REL
% button.
3. Depress the
EDIT
button. The right hand digit under the
REF
sub-display will start to flash.
4. Depress
REL
% or
HOLD
buttons until correct number is
selected for that display position.
5. Depress the
REC
button. The next digit to the right of 3
above will start to flash.
6. Repeat steps 4 and 5 until correct values for all four digits
under
REF
sub-display are entered.
7. After the correct
REF
value is entered, depress the
EDIT
button.
8. Measure the circuit or component being compared to the
programmed reference value. Results will be displayed as
a percentage in the lower left hand left hand sub-display.
9. Depress the
REL
% button or turn the rotary switch to exit
the function.
n. Two-Hold System
The two-hold system is a data hold feature that will
automatically store a stable reading under the 1 HOLD sub-
display in the lower left hand corner of the LCD. When a
new, stable reading is obtained, the reading under 1 HOLD
will be moved to 2 HOLD and the new reading will be
displayed under 1 HOLD
Depress the
HOLD
button to activate the feature.
Push the button again to de-activate the feature.
