Ametek Amrel PLA 2U, Руководство по эксплуатации

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M470039-01 REV-F Page 90
FOUR: REMOTE OPERATION
INTRODUCTION
The Progra mming Electronic Loa d is provided with GPIB and RS-232 Sta nda rd Commands for Progra mma ble
Instruments (SCPI) interfa ce for a utoma ted testing a pplica tions. The purpose of this section is to introduce the user to
SCPI comma nds used to control the eLoa d via remote communica tion.
NOTE: For a more comprehensive set of SCPI COMMANDS, please refer to the Programming Manual.
INTRODUCTION TO GPIB & RS-232 (SCPI) COMMANDS
The Genera l Purpose Interfa ce bus is synonymous with HP-IB sta nda rd bus used for controlling electronic instruments
with a computer. Also ca lled IEEE 488 bus beca use ANSI/IEEE Sta nda rds 488 -1978 defines it, 488.1-1987, a nd 488.2-
1987.
Sta nda rd Commands for Progra mma ble Instruments (SCPI) is a progra mming la ngua ge developed to remot ely control
different test a nd mea surement instruments over GPIB (IEEE 488) bus. SCPI functions with GPIB ha rdwa re conform to
the IEEE 488.2 Sta nda rd Digita l Interfa ce for Progra mma ble Instrumenta tion. It is a device independent command set
a nd is la yered on top of the ha rdwa re portion of IEEE 488.2. SCPI simplif ies the progra mming ta sk by defining a sin gle
comprehensive command set of progra mma ble instrumenta tion, rega rdless of type or ma nufa cturer. The sa me SCPI
comma nd can be applied to different cla sses of instruments. SCPI systems a re much ea sier to progra m and ma inta in. In
ma ny ca ses, you ca n intercha nge or upgra de instruments without ha ving to cha nge the test progra m. SCPI a lso a pplies to
RS-232 progra mming.
The electronic loa d's GPIB a ddress ca nnot be set via GPIB bus communica tion or program. The a ddress needs to be set
from the front pa nel keypa d in the MENU function.
OVERVIEW SCPI LANGUAGE
The SCPI la ngua ge uses a hiera rchica l structure in its progra mming synta x simila r to an inverted tree. The comma nd is
orga nized with root level comma nds positioned a t the top, with multiple sub commands below ea ch root -leve l command.
For exa mple, VOLTa ge, wh ich is a bra nch of SOURce, is a comma nd mnemonic a nd it forms a subtree of its own.
VOLTa ge ha s three sub-level commands: LEVel, SLEW, TLEVe l. At the end of a sub -level comma nd, you ca n atta ch a
pa rameter, a question ma rk (for query), a colon (command mnemonics sepa ra tor), a semicolon (for multiple comma nds in
a messa ge) or a n end of line termina tor. To execute a sub-level comma nd, you must specify the complete pa th from root -
level. Ea ch command statement is simply I/O ASCII da ta strings incorpora ted within high -level pro gra mming la ngua ge
(GW-BASIC, HP BASIC, Quick Ba sic, Pa sca l, etc.).
Command Message
VOLT:LEV 10;TLEV 15;:RES:TLEV? <NL>
Command Mnemonics Data
Command Statement
Query Indicator
Message Terminator
Command Statement Separator
Root Specifier