GW Instek GDM-8246 User Manual

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GDM-8246 MULTIMETER

PROGRAMMER MANUAL

CONTENTS PAGE

1. INTRODUCTION........................... ........... ...... ............. ........... .........

2. CONNECTING DMM VIA GPIB INTERFACE……………...

3. CONNECTING DMM VIA RS232 INTERFACE……………. 5

INPUT AND OUTPUT QUEUE………………………………..

5. COMMANDS AND SYNTAX…………………………………. 8

6. DETAILS OF COMMAND REFERENCE…………………… 21

7. STATUS AND ERROR REPORTING………………………....

PROGRAMMER MANUAL

1. INTRODUCTION

In the modern automatic measurement system, communication between equipments and computers is essential. The measured procedures can be varied with user’s testing programs, therefore, the Digital Multimeter can be operated remotely from an instrument controller or computer across the RS232 interface (optional) or GPIB (optional).

Interface selection and setup

Press [SHIFT][SET] in sequence into SET mode, then press [RS-232] or [GPIB] the white characters with blue background to set the RS232 OR GPIB interface. If the indicator of negative sine lights, the value

displayed on the front panel is the current setting value. Use [▲][▼] can adjust the baud rate (or GPIB address). Finally, press [ENTER] to store

the setup or pres s [SH IF T] to c anc el th e s etup .

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2. CONNECTING THE DIGITAL MULTIMETER VIA GPIB INTERFACE

The GPIB interface capabilities:

The GPIB interface of the Digital Multimeter corresponds to the standard of IEEE488.1-1987, IEEE488.2-1992 and SCPI-1994. The GPIB interface functions are listed as follows: SH1(Source Handshake) : The DMM can transmit multilane

messages across the GPIB.

AH1(Acceptor Handshake) : The DMM can receive multilane

messages across the GPIB.

T6(Talker) : Talker interface function includes basic

talker, serial poll, and unaddress if MLA capabilities, without talk only mode function.

L4 (Listener) : The DMM becomes a listener when the

controller sends its listen address with the ATN (attention) line asserted. The DMM does not have listen only capability.

SR1 (Service Request) : The DMM asserts the SRQ (Service

request) line to notify the controller when it requires service.

RL1 (Remote/Local) : The DMM responds to both the GTL(Go

to Local) and LLO(Local Lock Out) interface messages.

PP0 (Parallel Poll) : The DMM has no Parallel Poll interface

function.

DC1 (Device Clear) : The DMM has Device clear capability to

return the device to power on status.

DT0 (Device Trigger) : The DMM has no Device Trigger

interface function.

C0 (Controller) : The DMM can not control other devices.

PROGRAMMER MANUAL

Notes for GPIB installation When the Digital Multimeter is set up with a GPIB system, please check

the following th i ngs :

z Only a maximum of 15 devices can be connected to a single GPIB

bus.

z Do not use more than 20m of cable to connect devices to a bus. z Connect one device for every 2m of cable used. z Each device on the bus needs a unique device address. No two

devices can share the same device address.

z Turn on at least two-thirds of the devices on the GPIB system while

using the system.

z Do not use loop or parallel structure for the topology of GPIB

system.

Computer’s Connection A personal computer with a GPIB card is the essential facilities in order

to operate the Digital Multimeter via GPIB interface. The connections between DMM and co mp uter ar e following :

I. Connect one end of a GPIB cable to the computer. II. Connect the other end of the GPIB cable to the GPIB port on

the Digital Multimeter. Turn on the Digital Multimeter. Turn on the computer.

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PROGRAMMER MANUAL

The GPIB connection testing If you want to test whether the GPIB connection is working or not, you

can send a GPIB command from computer. For instance, the query command

*idn?

should return the Manufacturer, model number, and firmware version in the following format:

GW.Inc,GDM-8246,FW1.00

If you do not receive a proper response from the DMM, please check if the power is on, the GPIB address is correct, and all cable connections are active.

PROGRAMMER MANUAL

3. CONNECTING THE DIGITAL MULTIMETER VIA

RS232 INTERFACE

The RS232 interface capabilities:

The RS232 interface provides a point-to-point connection between two items of equipment such as a comp uter and the DMM. There are some parameters you need to set on the both sides. Once you have set these parameters, you can control the DMM through the RS232 interface.

z Baud rate: You can set rates of 1200, 2400, 4800 or 9600 baud. z Parity bit: none. z Data bit: 8 bits. z Stop bit: 1 stop bit. z Data flow control: none.

Notes for RS232 installation

The DMM is a DTE device with a 9-pin D-type shell RS232 connector located on the rear panel. Figure 1 shows the equipment of 9-pin connector (male) with its pin number assignments. Figure 2 shows the wiring configuration for DB9 to DB9. When the Digital Multimeter is set up with a RS232 interface, please check the following points:

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z Do not connect the output line of one DTE device to the output line

of the other.

z Many devices require a constant high signal on one o r more input

pins.

z Ensure that the signal ground of the equipment is connected to the

signal ground of the external device.

z Ensure that the chassis ground of the equ ipment is connected to the

chassis ground of the external device.

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PROGRAMMER MANUAL

z Do not use more than 15m of cable to connect devices to a PC. z Ensure the same baud rate is used on the device a s the one used on

PC terminal.

z Ensure the connector for the both side of cable and the internal

connected line are met the demand of the instrument.

1. No connection

2. Receive Data(RxD) (input)

3. Transmit Data(TxD) (output)

4. No connection

5. Signal Ground(GND)

6. No connection

7. No connection

8. No connection

9. No connection

Figure 1 Pin assignments of the RS232 connector on the rear panel for DB-9-D

PROGRAMMER MANUAL

EQUIPMENT

(DB9, DTE)

Pin2

Pin3

COMPUTER

(DB9, DTE)

Pin2

Pin3

Pin5 Pin5

Figure 2 Wiring configuration for DB9 to DB9

Computer’s Connection

A personal computer with a COM port is the essential facilities in order to operate the Digital Multimeter via RS232 interface.

The connections between DMM and co mp uter are a s follows:

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I. Connect one end of a RS232 cable to the computer. II. Connect the other end of the cable to the RS232 port on the

Digital Multimeter.

III. Turn on the Digital Multimeter. IV. Turn on the computer.

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The RS232 connection testing

If you want to test whether the RS232 connection is working or not, you can send a command from computer. For instance, using a terminal program send the query command

*idn?

should return the Manufacturer, model number, serial number and firmware version in the following format:

GW.Inc,GDM-8246,FW1.00

If you do not receive a proper response from the DMM, please check if the power is on, the RS232 baud rate are the same on both sides, and all cable connections are active.

4. INPUT AND OUTPUT QUEUE

The design of 128 bytes input queue and 128 bytes output queue for storing the pending commands or return messages is to prevent the transmitted commands of remote control and return messages from missing. As the maximum stored capacity for Error/Event Queue is 20 groups of messages, it should be noted that input data exceeding the capacity by using these buffers will cause data missing.

5. COMMANDS AND SYNTAX

The GPIB commands of the Digital Multimeter are compatible with

IEEE-488.2 and SCPI standards

SCPI

SCPI (Standard Commands for Programmable Instruments) is a standard that created by an international consortium of the major test and measurement equipment manufacturers. The IEEE-488.2 adopted by SCPI to provide common commands for the identical functions of different programmable instruments.

syntax has been

PROGRAMMER MANUAL

Figure 3 the relationship between IEEE-488.1, IEEE-488.2, and SCPI

SCPI

Common Command & Queries

Syntax & Status Data Structure

IEEE-488.2 IEEE-488.2

SCPI

Interface Function

AABBCCDD

SCPIIEEE-488.1

As shown in the figure 3, the IEEE-488.1 standard locates at layer A, the layer A belongs to the protocol of interface function on the GPIB bus. The source handshake (SH), acceptor handshake (AH) and talker are included to this layer (10 in terface functions totally). At layer B, the syntax and data structure could be the essence of entire IEEE-488.2 standard. The syntax defines the function of message communication, which contain the <PROGRAM MESSAGE> (or simply “commands”) and <RESPONSE MESSAGE>. The two kinds of messages represent the syntax formation of device command and return value. The data structure is the constitution of status reporting, which IEEE-488.2 standard have been defined.

The common commands and quer ies are included to layer C. Commands and queries can be divided into two parts: mandatory and optional. Commands modify control settings or tell the instrument to perform a specific action. Queries cause the instrument to send data or status information back to the computer. A question mark at the end of a

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PROGRAMMER MANUAL

command identifies it as a query. Layer D is interrelated with device information. Different devices have

different functions. SCPI command sets belong to this layer.

Command Syntax

If you want to transfer any instructions to an instrument, and comply with SCPI, there are three basic elements must be included.

z Command header z Parameter (if required) z Message terminator or separator

Command Header

The command header ha s a hierarchical structure that can be represented by a command tree (Figure 4). The top level of the tree is the root level. A root node is located at the root level. A root node and one or more lower-level nodes form a header path to the last node called the leaf node.

:SYSTem

Root node

:ERRor

:AUTO

Lower-level node

:STATe :STARt :CYCLe

Leaf Node

Figure 4: Tree hierarchy

PROGRAMMER MANUAL

The command header is configured b y header path and leaf node. Figure 5 shows the command header for the leaf node indicated in Figure 4.

Figure 5 Command Header

Parameter

If the commands have parameters, the values have to be included. In this manual, when we expressed the syntax of the command, the < > symbols are used for enclosing the parameter type. For instance, the syntax of the command in Figure 6 includes the Boolean parameter type.

NOTE: Do not include the <, >, or | symbols when entering the actual value for a parameter.

Figure 6 Command Header with Parameter

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Table 1 defines the Boolean and other parameter types for the Digital Multimeter.

Parameter Type Description Example

Boolean Boolean numbers or

0, 1

values

NR1 Integers 0, 1, 18 NR2 Decimal numbers 1.5, 3.141, 8.4 NR3 Floating point numbers 4.5E-1, 8.25E+1 String Alphanumeric characters “No error”

Table 1: Parameter Type s for Sy ntax Desc ript ions

Message Terminator and Message Separator

I. GPIB message terminators

In accordance with IEEE 488.2 standard, any of the following message terminators are acceptable:

z LF

END Line feed code (hexadecimal 0A) with END

message

PROGRAMMER MANUAL

II. RS232 message terminators

As there is no signal of end message on RS232 bus, therefore, use LF as message terminator. When a series of commands are sent to the instrument, it must add a LF to be a judgment for message terminator. As for query command, the return message of the instrument is also added a LF for PC to judge message terminator.

Entering Commands

The standards that govern the command set for the Digital Multimeter allow for a certain amount of flexibility when you enter commands. For instance, you can abbreviate many commands or combine commands into one message that you send to the Digital Multimeter. This flexibility, called friendly listening, saves programming time and makes the command set easier to remember and use.

Command Characters

The DMM is not sensitive to the case of command characters. You can enter commands in either uppercase or lowercase.

You can execute any command with white space char acters. You must, however, use at least one space between the parameter and the command header

z LF Line feed code z <dab>

END Last data byte with END message

These terminators are compatible with most application programs. A semicolon separates one co mmand from another when the commands appear on the same line.

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Abbreviating Commands

Most commands have a long form and a short form. The listing for each command in this section shows the abbreviations in uppercase. For instance, you can enter the query :CONFigure:VOLTage:DC 0 simply as :CONF:VOLT:DC 0

Because the Digital Multimeter hypothesis that a command starts from the root, you have the option of beginning the initial command header with a colon (:).

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PROGRAMMER MANUAL

Combining Commands

You can use a semicolon (;) to combine commands. But continuously query command will cause message missing. For example: :READ?;:VAL?

If the command that follows the semicolon has a different header path from the root level, you must use a colon to force a return to the root level:

:CONF:VOLT:DC 0;:CALC:SDBM:STAT 1 If the command that follows th e semico lon has the sa me head er path, you

may omit the colon and the path and state only the new leaf node. For example:

: CONF:VOLT:DC 0;:CONF:CURR:DC 0 is equal to

: CONF:VOLT:DC 0;:CURR:DC 0

You can combine commands and queries into the same message. Note, for example, the following combination:

PROGRAMMER MANUAL

General Setting Commands

Table 2 lists the general setting commands that control and query the settings of the DMM.

Table 2: General Setting Commands

Command Explanation

:CONFigure:AUTo? Returns Auto-range mode on or off. :CONFigure:AUTo <Beolean> Sets Auto-range mode on or off.

:CONFigure:RANGe? Returns the range of the present

function.

:CONFigure:MODe? Returns the total value of the

selected calculation mode.

:CONFigure:FUNCtion? Returns the present selected

function. :CONFigure:CAPacitance <NR2> Sets capacitance function and range. :CONFigure:CONTinuity Sets continuity function.

: CONF:VOLT:DC 0;:READ?

Synopsis of Commands

The tables in this section summarize the command of the Digital Multimeter. These tables divide the commands into four functional classifications:

z General Setting Commands z Calculating Commands. z Status Commands z Miscellaneous Commands

The tables also provide a brief explanation of each command.

⎯ 14 ⎯

:CONFigure:CURRent:AC <NR2> Sets AC current function and range. :CONFigure:CURRent:DC <NR2> Sets DC current function and range. :CONFigure:CURRent:ACDC <NR2> Sets AC+DC current function and

range. :CONFigure:DIODe Sets diode function.

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:CONFigure:SFRequency Sets frequency function. :CONFigure:RESistance <NR2> Sets resistance function and range. :CONFigure:VOLTage:AC <NR2> Sets AC voltage function and range. :CONFigure:VOLTage:DC <NR2> Sets DC voltage function and range. :CONFigure:VOLTage:ACDC <NR2> Sets AC+DC voltage function and

range.

:CONFigure:VOLTage:DCAC <NR2> Sets Ripple voltage function and

range.

:READ? Returns the value displayed on the

primary and secondary display

:VALue? Returns the value displayed on the

primary display.

:SVALue? Returns the value displayed on the

secondary display.

PROGRAMMER MANUAL

Calculation Commands

:CALCulation: LIMit:STATe? Returns Compare mode on or off.

:CALCulation: LIMit:STATe <Boolean>

:CALCulation: LIMit:LOWer?

:CALCulation: LIMit:LOWer <NR2>

:CALCulation: LIMit:UPPer?

:CALCulation: LIMit:UPPer <NR2>

:CALCulation: LIMit:FAIL?

:CALCulation:MAXimum?

:CALCulation:MAXimum <Boolean>

Sets Compare mode on or off.

Returns the value of the lower limit.

Sets the value of the lower limit.

Returns the value of the upper limit.

Sets the value of the upper limit.

Returns the limit result.

Returns the MAX mode on or off.

Sets the MAX mode on or off.

⎯ 16 ⎯

:CALCulation:MINimum?

:CALCulation:MINimum <Boolean>

:CALCulation: RELation: STATe <NR1>

:CALCulation:RELation: STATe?

:CALCulation:RELation:DATa?

:CALCulation:RELation:DATa <NR2>

⎯ 17 ⎯

Returns the MIN mode on or off.

Sets the MIN mode on or off.

Sets REL mode on or off.

Returns REL mode on or off.

Returns the reference value of the REL mode.

Sets the reference value of the REL mode.

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PROGRAMMER MANUAL

:CALCulation:SDMB:STATe?

:CALCulation: SDMB:STATe <Boolean>

:CALCulation: SDMB:REFerence?

:CALCulation: SDMB:REFerence <NR1>

:CALCulation:HOLD?

:CALCulation:HOLD <NR1>

Returns DBM mode on or off.

Sets DBM mode on or off.

Returns the reference impedance value of the DBM mode.

Sets the reference impedance value of the DBM mode.

Returns the hold and auto-hold on or off.

Sets the hold and auto-hold on or off.

z Stat us Command s

Table 3 lists the status commands that set and query the various registers and queues that make up the status and event structure of the Digital Multimeter.

Table 3: Status Commands

*CLS Clears the status data structures.

*ESE <NR1>

*ESE?

Sets the Event Status Enable Register (ESER).

Returns contents of Event Status Enable Register (ESER).

*ESR? Returns and clear the contents of

Standard Event Status Register (SESR).

PROGRAMMER MANUAL

*SRE <NR1> Sets contents of Service Request

Enable Register (SRER).

*SRE? Returns contents of Service

Request Enable Register (SRER).

*STB? Reads Status Byte Register

(SBR).

:STATus:OPERation:CONDition? Returns the contents of the

OPERation condition register. Returns NR1.

:STATus:OPERation:ENABle <NR1>

:STATus:OPERation:ENABle? Returns the contents of the enable

:STATus:OPERation:EVENt? Query the contents of the OPERation

Sets the contents of the enable mask for the OPERation event register.

mask for the OPERation event register. Returns NR1.

Event register.

:STATus:PRESet Preset s the OPERation and

QUEStionable status registe rs.

:STATus:QUEStionable:CONDition? Returns the contents of the

OPERation condition register. Returns NR1.

:STATus:QUEStionable:ENABle <NR1>

:STATus:QUEStionable:ENABle? Query the contents of the

:STATus:QUEStionable:EVENt? Query the contents of the

Sets the contents of the enable mask for the QUEStionable enable register.

Questionable Enable register.

QUEStionable Event regi ster.

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z Miscellaneous Commands

Table 4 lists the miscellaneous commands that control general housekeeping functions of the Digital Multimeter.

Table 4: Miscellaneous Commands

*IDN? Returns instrument identification. *OPC Reports when operation is completed by

setting the Operation Complete bit in SESR.

*OPC? Reports when operation is completed. Same as

*OPC except returns a 1 to the output queue and dose not set the SESR bit.

*RST Resets the protection levels and states, resets

the current and voltage levels to zero, sets the output off, and sets memory section to 00.

*WAI Wait to continue. This command forces

sequential operation of commands. This command is required by IEEE-488.1-1987. The DMM, however, forces sequential operation of commands by design.

:SYSTem:ERRor? Read the next item from the error/event queue. :SYSTem:VERSion? Returns the SCPI version level.

PROGRAMMER MANUAL

6. DETAILS OF COMMAND REFERENCE

Each command in this chapter will give a detailed description. The examples of each command will be provided and what query form might return.

*CLS (no query form)

Function: Clear all event status data register. This includes the Output Queue, Operation Event Status Register, Questionable Event Status Register, and Standard Event Status Register.

Syntax: *CLS Examples: *CLS clears all event registers.

*ESE

Function: Set or return the bits in the Event Status Enable Register (ESER). The ESER enables the Standard Event Status Register (SESR) to be summarized on bit 5 (ESB) of the Status Byte Register (SBR).

Syntax: *ESE <NR1>

*ESE?

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<NR1> is in the range from 0 through 255. Returns: <NR1> is a number from 0 to 255 that indicates the decimal value of the

binary bits of the ESER.

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Examples: *ESE 65 sets the ESER to binary 0100 0001.

If the ESER contains the binary value 1000 0010, the *ESE? will return the value of 130.

*ESR? (query only)

Function: Return and clear the contents of the Standard Event Status Register (SESR).

Syntax: *ESR? Returns: <NR1> is a number from 0 to 255 that indicates the decimal value of the

binary bits of the ESER. Examples: If the ESER contains the binary value 1100 0110, the *ESR? will return

the value of 198.

*IDN? (query only)

PROGRAMMER MANUAL

Examples: *IDN? Returns

GW_Inc, GDM-8246, FW1.00

*OPC

Function: The command form (*OPC) sets the operation complete bit (bit 0) in the Standard Event Status Register (SESR) when all pending operations are finished.

The query form (*OPC?) tells the Digital Multimeter to place an ASCII 1 in the Output Queue when the DMM comple tes all pend ing opera tions.

Syntax: *OPC

*OPC? Returns: 1

*RST (no query form)

Function: Set all control settings of DMM to 1000V DCV range but does not purge stored setting. The equivalent panel control will be set as below:

Function: Return the uniq ue id entif ic ation cod e of th e DMM.

Syntax: *IDN? Returns: <string> includes Manufacturer, model number, serial number and

firmware version.

⎯ 22 ⎯

*SRE

Function: Set the contents of the Service Request Enable Register (SRER). The query form returns the contents of the SRER. Bit 6 of the SRER is always zero. The bits on the SRER correspond to the bits on the SBR.

Syntax: *SRE <NR1>

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*SRE? Returns: <NR1> is in the range from 0 through 255. Examples *SRE 7 sets bits of the SRER to 0000 0111.

If the *SRE? returns 3, the SRER is set to 0000 0011.

*STB? (query only)

Function: The query of the Status Byte register (SBR) with *STB? will return a decimal number representing the bits that are set (true) in the status register.

Syntax: *STB? Returns: <NR1> is in the range from 0 through 255. Examples:

*STB? returns 81, if SBR contains the binary value 0101 0001.

*WAI (no query form)

Function: WAI prevents the programming instrument from executing further commands or queries until all pending operations are finish ed.

Syntax: *WAI

PROGRAMMER MANUAL

:CONFigure:AUTo

Function: Set or query the auto-range mode on or of f.

Syntax: :CONFigure:AUTo? :CONFigure:AUTo <Boolean> <Boolean> can be 0(off) or 1(on)

Returns: 0/1 Examples: :CONFigure:AUTo 1 Set to auto-range mod e.

If it is in the auto-range mode, the command of :CONFigure:AUTo? Will return the value of 1.

:CONFigure:RANGe?(query only)

Function: Set or query the range of th e p resen t fun ction.

Syntax: :CONFigure:RANGe?

Returns: <NR2>

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Examples: :CONFigure:RANGe? might return 50.000 to indicate the 50V range at

DCV. Please refer to the representative unit for every function range as fo llows:

Table 6-1:

Voltage V Capacitance nF

Current mA Diode V Resistance kohm Continuity kohm Frequency kHz dBm dBm

:CONFigure:MODe?(query only)

Function:

Return the total value of the selected calculation mode.

Syntax: :CONFigure:MODe?

Returns: <NR1> is in the range from 0 through 255. Examples: :CONFigure:MODe? might return 1 to indicate the MIN mode to be

slected.

PROGRAMMER MANUAL

Table 6-2:

Calculation Function Corresponding Value

MIN 1

MAX 2

HOLD 4

AUTOHOLD 8

dBm 16 REL 32

COMP 64

:CONFigure:FUNCtion?(query only)

Function:

Return the present selected function.

Syntax: :CONFigure:FUNCtion?

Returns: String Examples: :CONFigure:FUNCtion? might return “DCV” to indicate the present DC

voltage function. Please refer to the re turn ed mess age for every fun ction as fo llows :

Table 6-3:

Please refer to the representative total value for every attached calculation mode as follows:

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Function Description DC Voltage DCV AC Voltage ACV

AC+DC Voltage AC+DCV

ACV + Frequency Hz+ACV

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DC Current DCA AC Current ACA

AC+DC Current AC+DCA

ACA + Frequency Hz+ACA

Resistance OHM

Capacitance CAPACITANCE

Diode DIODE

Continuity CONT

Ripple RIPPLE

:CONFigure:CAPacitance

Function: Set capacitance function and the range.

Syntax: :CONFigure:CAPacitance <NR2>

Examples: :CONFigure:CAPacitance 0 sets to capacitance function and auto-range. :CONFigure:CAPacitance 30 sets to capacitance function and 50nF

range.

PROGRAMMER MANUAL

Examples: :CONFigure:CONTinity sets the continuity function. Please refer to the Tabl e 6-1.

:CONFigure:CURRent:DC <NR2>

Function:

Set the DC current function and range.

Syntax: :CONFigure:CURRent:DC <NR2>

Examples: :CONFigure:CURRent:DC 0 sets the DC current function and

auto-range. :CONFigure:CURRent:DC 1.5 sets the DC current function and 5mA range.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:CURRent:AC <NR2>

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:CONTinuity

Function:

Set the continuity function

Syntax: :CONFigure:CONTinity

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Function:

Set the AC current function and range.

Syntax: :CONFigure:CURRent:AC <NR2>

Examples: :CONFigure:CURRent:AC 0 sets the AC current function and

auto-range. :CONFigure:CURRent:AC 1.5 sets the AC current function and 5mA range.

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Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:CURRent:ACDC <NR2>

Function:

Set the AC+DC current function and range.

Syntax: :CONFigure:CURRent:ACDC <NR2>

Examples:

:CONFigure:CURRent:ACDC 0 sets the AC+DC current function and auto-range. :CONFigure:CURRent:ACDC 1.5 sets the AC+DC current function and 5mA range.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:DIODe

Function:

Set the DC diode function.

Syntax: :CONFigure:DIODe

Examples: :CONFigure:DIODe sets diode function.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:SFRequency

Function:

PROGRAMMER MANUAL

Set the frequency function in the AC mode.

Syntax: :CONFigure:SFRequency

Examples: :CONFigure:SFRequency sets the frequency function.

:CONFigure:RESistance <NR2>

Function:

Set the resistance function and range.

Syntax: :CONFigure:RESistance <NR2>

Examples: :CONFigure:RESistance 0 sets the resistance function and auto-range.

:CONFigure:RESistance 39 sets the resistance function and 50 kohm range.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:VOLTage:DC <NR2>

Function:

Set the DC voltage function and range.

Syntax: :CONFigure:VOLTage:DC <NR2>

Examples: :CONFigure:VOLTage:DC 0 sets the DC voltage function and auto-range.

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:CONFigure: VOLTage:DC 12 sets the DC voltage function and 50V range.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:VOLTage:AC <NR2>

Function:

Set the AC voltage function and range.

Syntax: :CONFigure:VOLTage:AC <NR2>

Examples: :CONFigure:VOLTage:AC 0 sets the AC voltage function and

auto-range. :CONFigure: VOLTage:AC 12 sets the AC voltage function and 50V range.

Please refer to the unit for every range shown as Table 6 -1.

PROGRAMMER MANUAL

and 50V range. Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:VOLTage:DCAC <NR2>

Function:

Set the DCAC voltage function and range.

Syntax: :CONFigure:VOLTage:DCAC <NR2>

Examples: :CONFigure:VOLTage:DCAC 0 sets the Ripple voltage function and

auto-range. :CONFigure: VOLTage:DCAC 41 sets the Ripple voltage function and 50V range.

Please refer to the unit for every range shown as Table 6 -1.

:CONFigure:VOLTage:ACDC <NR2>

Function:

Set the ACDC voltage function and range.

Syntax: :CONFigure:VOLTage:ACDC <NR2>

Examples: :CONFigure:VOLTage:ACDC 0 sets the AC+DC voltage function and

auto-range. :CONFigure: VOLTage:ACDC 12.5 sets the AC+DC voltage function

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PROGRAMMER MANUAL

:READ?(query only)

Function: Returns the value displayed on the primary and secondary display with

14 characters totally. Syntax:

:READ? Examples: :READ? Might return “ NONE ,+0.0000” when the current function is in

the DC voltage.

:VALUE?(query only)

Function: Returns the value displayed on the primary and secondary display with 7

characters totally. Syntax:

:VALUE? Examples: :VALUE? might return “+0.0000” when the current function is in the DC

voltage.

:SVALue?(query only)

PROGRAMMER MANUAL

Syntax: :SVALue?

Examples: :SVALue? might return “ -OL- ” when th e current function is in the dBm

mode.

:CALCulation:LIMit:STATe

Function:

Returns or sets the compare mode on or off.

Syntax: :CALCulation:LIMit:STATe? :CALCulation:LIMit:STATe <Boolean> <Boolean> can be o(off) or 1(on) Returns: 0/1

Examples: :CALCulation:LIMit:STATe? might return 1 in the compare mode. :CALCulation:LIMit:STATe 1 sets the compare mode.

:CALCulation:LIMit:LOWer

Function:

Returns the value displayed on the primary and secondary display with 6

characters totally.

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Function:

Returns or sets the value of the lower limit in the compare mode.

Syntax:

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PROGRAMMER MANUAL

:CALCulation:LIMit:LOWer? :CALCulation:LIMit:LOWer <NR2>

Examples: :CALCulation:LIMit:LOWer? might return +1.0000 in the DC voltage

function. :CALCulation:LIMit:LOWer 1.0000 sets 1.0000 DC voltage at the lower

limit in the DC voltage function.

:CALCulation:LIMit:UPPer

Function: Returns or sets the v alu e of th e upp er l imit in the comp ar e mod e. Syntax:

:CALCulation:LIMit:UPPer? :CALCulation:LIMit:UPPer <NR2>

Examples: :CALCulation:LIMit:UPPer? might return +1.0000 in the DC voltage

function. :CALCulation:LIMit:UPPer 1.0000 sets 1.0000 DC voltage at the upper

limit in the DC voltage function.

:CALCulation:LIMit:FAIL?

Function:

Returns limit result.

Syntax:

PROGRAMMER MANUAL

:CALCulation:LIMit:FAIL? Examples: 0(low)/1(pass)/2 (hig h)

:CALCulation:LIMit:FAIL? might return 1 means the reading is pass.

:CALCulation:MAXimum

Function: Returns or sets the MAX mode on or off. Syntax:

:CALCulation:MAXimum? :CALCulation:MAXimum <Boolean> <Boolean> can be o(off) or 1(on).

Examples: :CALCulation:MAXimum? might return 1 in the MAX mode. :CALCulation:MAXimum 1 sets the MAX mode.

:CALCulation:MINimum

Function: Returns or sets the MIN mode on or off. Syntax:

:CALCulation:MINimum? :CALCulation:MINimum <Boolean>

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<Boolean> can be o(off) or 1(on). Examples:

:CALCulation:MINimum? might return 1 in the MIN mode. :CALCulation:MINimum 1 sets the MIN mode.

:CALCulation:RELation:STATe

Function: Returns or sets the REL mode on or off. Syntax:

:CALCulation:RELation:STATe? :CALCulation:RELation:STATe <Boolean> <Boolean> can be o(off) or 1(on).

Examples: :CALCulation:RELation:STATe? might return 1 in the REL mode. :CALCulation:RELation:STATe 1 sets the REL mode.

:CALCulation:RELation:DATa

Function:

Returns or sets the reference value in the REL mode.

Syntax: :CALCulation:RELation:DATa? :CALCulation:RELation: DATa <NR2>

PROGRAMMER MANUAL

Examples: :CALCulation:RELation:DATa? might return +1.0000 in DC voltage

function. :CALCulation:RELation:DATa 1.0000 sets 1.0000 DC voltage at the

reference standard value. Please refer to the unit for every range shown as Table 6 -1.

:CALCulation:SDBM:STATe

Function: Returns or sets the SDBM mode on or off. Syntax:

:CALCulation:SDBM:STATe? :CALCulation:SDBM:STATe <Boolean> <Boolean> can be o(off) or 1(on).

Examples: :CALCulation:SDBM:STATe? might return 1 in the dBm mode. :CALCulation:SDBM:STATe 1 sets the dBm mode.

:CALCulation:REFerence:SDBM:REFerence

Function: Returns or sets the reference impedance in the dBm mode. Syntax:

:CALCulation:SDBM:REFerence?

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:CALCulation: SDBM:REFerence <NR1> Examples:

:CALCulation:SDBM:REFerence? might return 0600 in DC voltage function.

:CALCulation: SDBM:REFerence 600 sets 600 ohm DC voltage at the reference standard value.

Please refer to the unit for every range shown as Table 6-4:

Table 6-4: Selectable Reference Impedance in ohms:

2 93 250 1000 4 110 300 1200

8 124 500 8000 16 125 600 50 135 800 75 150 900

:CALCulation:HOLD

Function: Returns or sets the Hold and Auto-hold mode on or off. Syntax:

:CALCulation:HOLD? :CALCulation:HOLD <Boolean> <Boolean> can be o(off), 1(hold),or 2(auto-hold).

Examples: :CALCulation:HOLD? might return 2 in the Auto-hold mode.

PROGRAMMER MANUAL

:CALCulation:HOLD 1 sets the Hold mode.

STATus:OPERation:CONDition? (query only)

Function: Return the contents of the OPERation r egister. The DMM, however, do not use the OPERation register to report any conditions.

Syntax: STATus:OPERation:CONDition? Returns: <NR1> Examples: STATus:OPERation:CONDition? returns 0.

STATus:OPERation:ENABle

Function: Set or query the enable mask that allows the masked conditions in the event register to be reported in the summary bit. If a bit is 1 (true) in the enable register and its associated event bit changes to 1 (true), the associated summary bit will change to 1 (true). Even though this is a 16-bit register, only 15 bits (bit 0 through bit 14) are used. Bit 15 always reads 0.

Syntax STATus:OPERation:ENABle <NR1>

STATus:OPERation:ENABle? <NR1> is an integer from 0 to 32767. Returns <NR1>

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Examples STATus:OPERation:ENABle 32767 sets all 15 bits of the register to 1.

If the STATus:OPERation:ENABle? returns 0, all 15 bits of the register are 0.

STATus:OPERation:EVENt (query only)

Function: Returns and clears the contents of the OPERation register.

Syntax: STATus:OPERation:EVENt? Returns: <NR1> Examples: STATus:OPERation:EVENt? returns 0.

STATus:PRESet

Function: Set the OPERation and QUESTionable enable reg isters to ze ros.

Syntax: STATus:PRESet

STATus:QUEStionable:CONDition? (query only)

Function: Return the contents of the QUEStionab le register. Reading the condition register is non-destructive.

PROGRAMMER MANUAL

Syntax: STATus:QUEStionable:CONDition? Returns: <NR1> Examples: STATus:QUEStionable:CONDition? returns 0.

STATus:QUEStionable:ENABle

Syntax: STATus:QUEStionable:ENABle <NR1>

STATus:QUEStionable:ENABle? <NR1> is an integer from 0 to 32767. Returns: <NR1> Examples: STATus:QUEStionable:ENABle 32767 sets all 15 bits of the register to

1. If the STATus:QUEStionable:ENABle? returns 0, all 15 bits of the

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STATus:QUEStionable:EVENt(query only)

Function: Return and clear the conten ts of the QUES tionable re gister. The response is a decimal value that summarizes the binary values of the set bits.

Syntax: STATus:QUEStionable:EVENt? Returns: <NR1> Examples: STATus:QUEStionable:EVENt? returns 0.

SYSTem:ERRor? (query only)

Function: Query the next error message from the Error/Event queue. The result of the query is the error number followed by the error text .

Syntax:

PROGRAMMER MANUAL

SYSTem:VERSion? (query only)

Function: Return the SCPI v ersio n o f the dev ice .

Syntax: SYSTem:VERSion? Returns:

1994.0

SYSTem:ERRor? Returns: <string> Examples: SYSTem:ERRor? returns 0, “No error”

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7. STATUS AND ERROR REPORTING

A set of status registers allows the user to quickly determine the DMM’s internal processing status. The status register, as well as the status and event reporting system, adhere to SCPI recommendations.

Structure of System

The sketch of the status and event reporting system is showed as figure 7. Each component of the sk etch represents a set of registers and queues that can read, report, or enable the occurrence of certain events within the system.

If a specific event in the DMM sets a bit in a status register, reading which can tell you what types of events have occurred.

Each bit in the status register corresponds to a bit in an enable register; the enable bit must be high for the event to be reported to the Status Byte Register.

A Service Request (SRQ) is the last event to occur. The SRQ requests an interrupt on the GPIB to report events to the system controller.

Status Registers

There are two kinds of status regis ters ar e included to th e DMM.

z OPERation Status Registers ( CONDition, EVENt, and ENABle) z QUEStionable Status Registers (CONDition, EVENt, and ENABle)

The lower level nodes: QUEStionable and OPERation each have three 16 bits registers: CONDition, EVENt, and ENABle. Figure 8 shows the sequential relationship between these three types of registers and the commands that relate to each regis ter.

PROGRAMMER MANUAL

QU EStionable Status

Voltage Overload Current Overload

Frequency Null Sense

Ohm Overload

Capacitance Overload

Limit Test Fail LO

Limit Test Fail HI

0 1 2

Not Used

5 6

Not Used

9 10 11 12 13

Not Used

OPE Ration Status

Not Used

Error/E v e n t Q u eu e

Output Queue

Standard Event Status Registers

Op e ra tion Co mple te

Device Dependent

Error

Execution Error

Command Error

0 1

Not Used

Qu ery E rro r

2 3 4 5

User

Request

Power On

Summ ary of IEEE 488.2 Status Structure Registers

Figure 7. A graphic representation of the status registers and their connections.

Status Byte Register

Not Used

E/E

QUES

ESB

RQS/MSS

6 7

OPER

SRQ

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Condition

Event

Enable

To SBR

Figure 8: Status registers and related commands

The CONDition register is a read-only register which monitors the present state of the instrument. The CONDition register updates in real time and the inputs are not latched or buffered. When a condition monitored by the CONDition register becomes true, the bit for that condition also becomes true (1). When the condition is false, the bit is 0. The read-only EVENt register latches any false-to-true change in condition. Once the bit in the EVENt register is set, it is no longer affected by changes in the corr esponding bit of the CONDition register. The bit remains set until the controller reads it. The command *CLS (Clear Status) clears the EVENt register.

QUEStionable Status Registers.

PROGRAMMER MANUAL

Table 4: QUEStionable Status Register

Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8

∗NU NU Limit Test

Fail HI

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

NU NU Frequency

ull Sense

Limit Test

Fail LO

NU NU NU

Capacitance

Overload

Current Overload

Ohm

Voltage

Overload

The command STATus:QUEStionable:CONDition? Reads the QUEStionable CONDition register but dose not clear it.

The command STATus:QUEStionable:EVENt? Reads the QUEStionable EVENt Status register and clears it.

OPERation Status Registers

Table 5 shows the bit designations of the 16 bit OPERation Status Register.

Table 5: OPERation Status Register

Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bi t 9 Bit 8

Table 4 shows the bit designations of the 16 bit QUEStionable Status Register.

NU NU NU NU NU NU NU

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

NU NU NU NU NU NU NU NU

∗

NU: not used

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Status Registers

There are two status registers are included to the DMM defined by IEEE-488.1 and IEEE-488.2 standards.

z Status Byte Register (SBR) z Standard Event Status Register (SESR)

Status Byte Register (SBR)

: The SBR (Table 6) su mmarizes the status of

all other registers and queues.

Table 6: Status By te R egi ste r (S BR)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bi t 0

OPER RQS/MSS ESB MAV QUES E/E NU NU

The bit 0 and 1 are not used, so these bits are always zero. The bit 2 (Error and Event) indicates an error code is waiting to be read in the Error Event Queue. The bit 3 (QUES, QUEStionable) is the summary bit for the QESR (QUEStionable Event Status Register). When the bit is high it indicates that status is enabled and present in the QUES. The bit 4 (MAV, Message Available) indicates that output is available in the output queue. The bit 5 (ESB, Event Status Bit) is the su mmary bit for the Standard Event Status Register (SESR). When the bit is high it indicates that st atus is enabled and present in th e SESR. The bit 6 (RQS, Request Service) is obtained from a serial poll and shows that the DMM requests service from the GPIB controller. The bit 7 (OPER, OPERation) is the summary bit for the OESR (OPERation EVENt STATus Register).

PROGRAMMER MANUAL

Use the serial poll or the *STB? Query to read the con tents of the SBR. The bits in the SBR are set and cl eared depending on the conten ts of the Standard Event Status Register (SESR), the Standard Event Status Register (SESR), and the Outpu t Queu e.

Standard Event Status Register (SESR)

: Table 7 shows the SESR

Table 7: Standard Event Status Register (SESR)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PON URQ CME EXE DDE QYE NU OPC

The bit 0 (OPC, Operation Complete) shows that the operation is completed. This bit is active when all pending operations are completed following an *OPC command. The bit 1 is always zero. The bit 2 (QYE, Query Error) indicates a command or query protocol error. The bit 3 (DDE, Device Error) shows that a device error occurred. The bit 4 (EXE, Execution Error) shows that an error occurred while the DMM was executing a command or query. The bit 5 (CME, Command Error) shows that an error occurred while the DMM wa s parsing a command or query. The bit 6 (USR, User Request) indicates the LOCAL button was pushed. The bit 7 (PON, Power On) shows that the DMM was powered on.

Use the *ESR? Query to read the SESR. Read the SESR and clear the bits of the registers so that the register can accumulate information about new events.

Enable Registers

The enable registers determine whether certain events are reported to the Status Byte Register and SRQ. The Digital Multimeter has the following enable registers.

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z Ev ent S tatus E nable Reg ister (ESER) z OPERatio n Enable Reg ister z QUEStionable Enable Register z Serv ice Request Enable Reg ister (SRER)

When one of the bits of the enable registers is high and the corresponding bit in the status register is high, the enable registers will perform a logical OR function, the output that controls the set bit of the Status Byte Register is high.

Various commands set the bits in the enable registers. The following sections describe the enable r egis ters and the co mmand s that set the m.

Event Status Enable Register (ESER)

: The ESER controls which types of events are summarized by the Event Status Bit (ESB) in the SBR. The bits of the ESER correspond to the bits of the SESR.

Use the *ESE command to set the bits in ESER. Use the *ESE? query to read it.

OPERation Enable Register

: Even though the OPERation Enable Register is present in the DMM, the OPERation registers do not report any conditions.

QUEStionable Enable Register

: The QUEStionable Enable Register controls which types of events are summarized by the QUES status bit in the SBR. Use the STATus:QUEStionable:ENABle command to set the bits in the QUEStionable Enable register. Use the STATus:QUEStionable:ENABle? query to read it.

Service Request Enable Register (SRER)

: The SRER controls which bits

in the SBR generate a service request. Use the *SRE command to set the SRER. Use the *SRE? qu ery to read

it.

PROGRAMMER MANUAL

Queues

The output queue is included to power supplies.

Output Queue

: The DMM store query responses in the output queue by succeeding the IEEE 488.2 protocol. If the DMM receives a new command or query message after a message terminator, the DMM will clear and reset this queue each time. The computer must read a query response before it sends the next command (or query) or it loses response to earlier queries.

Error/Event Queues

When an error or event occurs, the output queue store s the message. The output queue stores and reports the messages on a FIFO (first in firs t out) state. The SYSTem:ERRor? query reads the next item from the output queue. If output queue overflows, the error message is –350, “Queue overflow”; the queue can’t store or report succeeding messages till it is read or cleared.

Error Message

Table 8 lists the SCPI error message s for the D MM.

Table 8 The error messages for the DMM:

SCPI Error Code and Description

SESR Bit

0, “No error”

-100, “Command error” 5

-200, “Execution Error” 4

-221, “Settings conflict” 4

-222, “Data out of range” 4

-350, “Queue overflow” 3

-410, “Query INTERRUPTED” 2

-420, “Query UNTERMINATED” 2

-430, “Query DEADLOCKED” 2

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Specifications and Main Features

Frequently Asked Questions

User Manual