General calibration procedure – HP 6627A User Manual
Page 91

Calibration Procedures
91
Table A-1. Calibration Commands
Command
Header
Channel*
Range
Data
Syntax
(see Figure 5-2)
Calibration Mode
CMODE
0,1 (off,on)
C2
Set High Voltage
VHI
1,2,3,4
-
C3
Set Low Voltage
VLO
1,2,3,4
-
C3
Set High Current
IHI
1,2,3,4
-
C3
Set Low Current
ILO
1,2,3,4
-
C3
Calibrate Overvoltage
OVCAL
1,2,3,4
-
C3
Voltage Data
VDATA
1,2,3,4
see Table A-2
C5
Current Data
IDATA
1,2,3,4
see Table A-2
C5
*Channels 3 and 4 are not used in all models.
Table A-2. Voltage and Current Data Ranges
Voltage Range in Volts
Current Range in Amps
Vlo
Vhi
llo
Ihi
Output
Min
Max
Min
Max
Min
Max
Min
Max
40 W Low Voltage
0
0.1
18.5
20.5
0
0.15
4.5
5.3
40 W High Voltage
0.04
0.20
44
48
0
0.1
1.5
2.1
80 W Low Voltage
0
0.1
18.5
20.5
0.05
0.25
9
10.5
80 W High Voltage
0.04
0.20
44
48
0
0.1
3.5
4.2
General Calibration Procedure
This procedure causes the voltage of the specified output to go to full scale value. Take appropriate
precautions.
The following general procedure applies to any computer that you are using to control your power supply. This procedure
must be repeated for each output on your power supply. The calibration commands shown are the actual string commands
that must be sent to the power supply. Because the power supply will attempt to calibrate itself even when incorrect or
invalid readings are sent to it, it is recommended that you perform some type of error checking after steps 4, 5, and 8 to
ensure that the values sent to the supply are legitimate. Use the ranges in Table A-2 as a guide. If an error is detected
while in calibration mode, send CLR or turn the supply off to maintain the previous calibration constants. This will
prevent incorrect constants from being stored. See Table 5-8 for a list of errors.
Before you continue with this procedure, disconnect all loads from the supply, strap the supply for local sensing, and
connect the voltmeter to the + S and - S terminals as shown in the voltage calibration setup of Figure A-1.
Start with output channel 1 and use the following commands to calibrate your power supply: