PROGRAMMING
PRS-200 Series
13
7.3
Advanced Programming -
Software Drivers
Basic control of a PRS can be automated by writing
a function that accepts a numeric value and converts
it to the string using the method described previously.
If the PRS is to be used in an automated environment
where various models and options may be installed or
where interchangeability is a requirement, a
driver
can be written that abstracts the device specific func-
tions from the test sequence.
The PRS family of instruments are available in many
models (including inductance, resistance and capaci-
tance) ranges, (1milliOhm to 10MegaOhm) and with
various options. Information to create a more robust
driver to control a PRS instrument is listed below.
7.3.1 Determining the PRS Configuration
The IEEE 488.2 specification defines the *IDN string
as containing 4 sections separated by commas; the
manufacturer, the model, the serial number and the
revision of the instrument.
The Model section of the *IDN string of the PRS has
been encoded to provide information about the char-
acteristics of the specific instrument being used. For
example, a *IDN query to a PRS might return:
I E T L a b s , P R S - 2 0 0 - F - 6 - 1 0 0 m - 0 - 0 , D 6 -
0211201,D6
In our example above, the Manufacturer section con-
tains “IET Labs”, the Model section contains “PRS-
200-F-6-100m-0-0”, the Serial Number section “D6-
0211201” and the Revision section “D6”. The model
is split into 7 parts with dashes to identify:
Type
Version
Tolerance
Number of Decades
Least Significant Decade
Slot of LSD
Options
Type:
PRS
Resistance Substituter
Version:
200
201
202
Tolerance:
X:
0.01%
Q:
0.02%
A:
0.05%
B:
0.1%
C:
0.5%
F:
1%
G:
2%
H:
4%
LSD:
1m
1 milliOhm
10m
10 milliOhm
100m
100 milliOhm
1
1 Ohm
10
10 Ohm
100
100 Ohm
1K
1 KOhm
10K
10 KOhm
100K
100 KOhm
1M
1 MegaOhm
10M
10 MegaOhm
Note:
micro and Mega Ohms use the same
suffix letter; case indicates magnitude.
Open Cicuit / Short Circuit Option:
0
not equipped
1
Open Circuit option present
2
Short Circuit option present
3
Both OC/SC present
7.3.2 Instrument Initialization
Reset the unit to power up defaults using *RST
Check that the instrument is “in cal” by reading the
calibration date and compare it to current date/time
using CALibrate:DATe?
