IET Labs PRS-200 Series, Руководство по эксплуатации

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14
PRS-200 Series
PROGRAMMING
Chapter 7
PROGRAMMING
For example:
Value
Command
600,567.9
Ω Ω Ω Ω Ω
SOURce:DATA 0006005679
2,700,000
Ω Ω
Ω Ω
Ω
SOURce:DATA 0027000000
Values sent for decades not implemented in the PRS
are ignored. Setting a PRS with 4 decades and a mini-
mum resolution of 1,000.0
Ω
to 10,600,567.9 would
result in an actual value of 600,000
Ω.
For example:
Command Value
SOURce:DATA 0106005679
600,000
Ω Ω
Ω Ω
Ω
Optional Open Circuit (OC) and Short Circuit (SC)
are implemented as standard decades positioned at
the Most Significant Decade plus one. For example,
the Resistance String for the Open circuit and Short
circuit modes for a unit with a total of 7 decades are:
Open circuit
SOURce:DATA 001XXXXXXX
Short circuit
SOURce:DATA 002XXXXXXX
(where X = any Resistance String)
OC and SC modes may be used to create a “con-
trolled transition” between two values without con-
cern for transitional switching of the relays.
•
Output command for R1.
•
Output command for R1 plus a SC Mode Character.
•
Output command for R2 plus a SC Mode Character.
•
Output command for R2.
This technique also applies to the Open circuit mode.
OC/SC mode Character =
0, 4, 8, or absent for NORMAL operation
1, 5, or 9 for OPEN CIRCUIT operation -optional
2, 3, 6, or 7 for SHORT CIRCUIT operation -optional
7.1 Introduction
PRS-200 units equipped with IEEE or SERIAL op-
tions implement a consistent SCPI interface. A SCPI
command reference is included in Appendix A.
7.2 Command String Structure
Output is controlled in the form of a single SCPI com-
mand followed by a space and a 10 character Resis-
tance String. Each character in the string represents
the value of one decade, equivalent to one possible
manual thumbwheel switch on the front of the unit.
This Resistance String is constructed as:
•
The number is in units of 0.1
Ω Ω Ω Ω Ω
.
•
All 10 characters must be provided; the active charac-
ters are the ones that match the front panel thumb-
wheel decades.
•
The decade values are straight-reading, from left to
right. All preceding and trailing zeros must be included
to complete 10 characters; any other characters in those
spaces will be ignored.
•
A decimal point may not be included.
The Resistance String has a minimum resolution of
0.1
Ω
with this decade assigned to the right-most char-
acter in the string. To create the SCPI command:
•
Multiply the desired value, in ohms, by 10
•
Convert the integer portion of the value to a string,
•
Pre-pend 0’s to create a 10 character Resistance String
•
Combine with the “SOURce:DATA ” command.