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 subdisplay 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 subdisplay 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.