Vishay VT300, Technical Manual

Page: 67 / 86

Outputs and Digital Input
Configuring Analog Output
VT300 Technical Manual, Rev. A4
67
Doc # TM-VT300-EN
Parameter Description Values
CURRENT Effective range for current output . Sets the range to 0-
20mA or 4-20mA. Relevant only if
OUTPUT
and the hardware
jumper are set to current.
0-20, 4-20
RESOLUT.
Resolution . Specifies whether output should be in high
resolution if the display is showing high resolution.
DISP specifies that output should match display.
INIT specifies that output should be in low resolution even if
the display is showing high resolution.
DISP, INIT
OPERATION Enable analog output. Setting this parameter to NO
disables the analog output channel.
YES, NO
ZERO D/A* D/A output at zero , in voltage or mA. XX.XXX
FULL D/A* D/A output at maximum input , in voltage or mA. XX.XXX
* These parameters only appear if
CALIBRATION
is set to
USER
.
7.4.3
Calibrating D/A Converter
To calibrate D/A converter (0-10V):
1. Place jumper JP1 on PCB (761) for voltage output.
2. Power up the unit, press
MENU
and navigate to
SYSTEM
>
D/A CAL
.
3. Set parameters as follows:
CALIBRATION
=
USER
;
SCALE ERROR
=
0mA
;
OUTPUT
=
VOLT
;
MODE
=
NET
;
CURRENT
=
0-20
;
RESOLUT.
=
INT
;
OPERATION
=
YES
.
4. Skip D/A calibration and save the above settings by accessing
SYSTEM
>
1CAL
>
WRITE
.
5. Press
MENU
and navigate to
SYSTEM
>
TEST
>
D/A TEST
.
6. The display shows
00000
. Type
65535
. Press PRINT to output the value.
7. Use a voltmeter to measure the voltage at pins 2 (+) and 3 (-) of the analogue
output connector (J4). Record the value (in volts). Calculate a new value, which is:
100/recorded value. E.g. recorded value is 9.94, new value is 100/9.94=10.06.
This is the
full scale voltage
.
8. Press
MENU
and navigate to
SYSTEM
>
D/A CAL
.
9. Set the
CALIBRATION
parameter to
YES
. The calibration dialog starts.
10. When prompted for D/A zero, enter
00.000
.
11. When prompted for D/A span, enter the
full scale voltage
you calculated in step 7.
12. When you finish stepping through the dialog, exit the menu.
13. Access
SYSTEM
>
1CAL
>
WRITE
to save your settings.