Broad range of laboratory grade decade
substituters for applications requiring a cost effective programmable-impedance
unit controlled manually and by a computer.
Choice of Performance:
- PRS-200 Series - economical 1% accuracy
- PRS-201 Series - laboratory 0.1% accuracy
- PRS-202 Series - high accuracy to 0.01%
- PRTD Series - programmable RTD simulation.
Package Configuration: Convenient standard 19"
rack mounting or more portable benchtop versions are available.
Both single and dual units are available.
Low thermal emf: Specially selected relays along
with tellurium copper binding posts in sure minimum thermal emf
drift.
High Power: Power up to 100’s
of watts and high current options are available.
Combinations: Dual or combination resistance-capacitance-inductance
models may be configured.
Special Requirements: High voltage nonstandard
values, ultra low temp co or special programming needs can be
accommodated.
Rear Outputs: Single or dual front and rear outputs
are available with option RO.
Wide choice of impedance ranges: resistance, capacitance
and inductance of up to 10 decades may be specified. Resistance
may range from 1 mΩ to 100 MΩ.
PRTD: Low resistance versions with a fixed minimum
resistance setting (4 Ω or specified by customer) are suitable
for RTD (Resistance Temperature Detector) simulations. This design
virtually eliminates the effect of zero resistance and relay contact
resistance, providing the specified absolute accuracy over its
entire range.
High Power Options: Power dissipation requirements
of up to tens of Watts can be accommodated.
Short-Circuit (SC) and Open-Circuit (OC) Options:
Optional short-circuit and open-circuit modes of operation. These
states are controlled only in the REMOTE programming mode.
OC or Open Circuit operation gives the user an open circuit immediately
in series with the HI binding post. SC or Short Circuit operation
gives the user a short circuit across the HI and the LO binding
posts The short circuit impedance is very small, <20 mΩ
or as low as 5 mΩ. This is lower than the regular zero resistance
setting. In both these cases, the underlying resistance setting
is unaffected and may still be controlled.
Digital Display: Shows the configured value
either thumbwheel or remote setting on a matching LED display
above the thumbwheel switches. This is useful for confirming or
monitoring the selected command value, remote or local.
Remote Control And Programming
Control Options:
Thumbwheel: Standard feature on all models.
BCD: (Binary Coded Decimal): Use external digital
I/O lines to set decade values individually. Requires 4 TTL
lines per decade. The user provides his own control circuitry
IEEE.1: Our original computer interface which
supports the IEEE-488.1 or IEEE-1978 protocol is still available
to allow you to maintain compatibility with your legacy hardware
/ software investment. This may also be a more economical solution
for your control needs
IEEE: This is the most popular, world wide
interface standard for test and measurement equipment. With
this option, the PRS is compliant with IEEE-488.2 and SCPI 1994.0.
Features *IDN and cal date query, allowing you to improve your
instrument and calibration tracking capabilities. GPIB addressing
is controlled via DIP switches or commands on the GPIB bus.
RS232: This interface conforms to EIA-STD-RS-530;
with a 25 pin DTE interface. Choose from factory configurable
RS232 or RS422/RS485 differential modes.
The PRS is a standard DTE device in RS232 mode. Typical connection
to a controlling computer is made via a null-modem cable. This
is the default mode if not specified.
Specify RS422/485 mode when the PRS is in a remote location
or when communications port capacity is at a premium. The RS422/485
specification uses differential signalling to increase transmission
distances and to reduce communications errors in noisy environments.
When in 485 mode, the PRS is a listen-only device and configurable
to addresses 0-15. The internal 422/485 mode eliminates the
need for external signal adapters on the PRS.
When equipped with any remote control functionality, the PRS
front panel switch determines if REMOTE mode is enabled. Regardless
of remote control type, setting the front panel switch to the
LOCAL position always disables the re mote control “set”
value. Use of the IEEE GTL (go-to-local) command message returns
the PRS to LOCAL mode and the PRS output value to the thumbwheel
setting. GTL is an IEEE specific function and not applicable to
Serial or BCD equipped units.
Supported commands include: *IDN?, *CLS, *ESE, *ESE?, *ESR?, *IDN?,
*OPC, *OPC?, *PSC, *PSC?, *RCL, *RST, *SAV, *SRE, *SRE?, *STB,
*TRG, *TST? and *WAI.
When using the PRS in an environment where traceability is required,
test software can query the ‘*IDN’ and ‘CALibrate:DATe’
reg is ters at the beginning of each test sequence to record equipment
serial numbers and check the calibration date against the current
date.
A typical test sequence might include:
| Init the instrument |
|
*RST |
| retrieve S/N & caldate |
|
*IDN?;CAL:DATE? |
Loop Begin
| set PRS value |
|
SOURCe:DATA 000050000000 |
| check for errors |
|
SYST:ERR? or *STB? |
| make test meas… |
|
|
Loop End
| Return to known state |
|
SOURCe:DATA 000000000000 |
| Send Go-To-Local cmd |
|
|
The remote output value is set by sending a ‘SOURCe:DATA’
command followed by a string that represents the digits as they
would be selected using the thumbwheels. Leading and trailing
zeros are required to set each decade properly; the decimal point
is not used.
For example; the PRS-202 has a least significant digit value of
0.01 Ohms and a remote logic maximum of 12 command decades. To
set a value of 500,000.45 Ohms, the command string would be:
SOURCe:DATA 000050000045
The PRS-201 has a least significant digit value
of 0.1 Ohms and a remote logic maximum of 10 command decades.
To set a value of 2,500.8 Ohms, the command string would be:
SOURCe:DATA 0000025008
Request the LabVIEW drivers to quickly integrate
the PRS into your test environment. These drivers are built based
on the NI driver template, and include a virtual front panel application.
The LabVIEW runtime engine is included with the drivers for simple
remote control operation. |
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