GW Instek PST User Manual

PST & PSS & PSH SERIES PROGRAMMABLE POWER SUPPLY

PST & PSS & PSH SERIES PROGRAMMABLE POWER SUPPLY

PROGRAMMER MANUAL

CONTENTS PAGE

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

2. CONNECTING POWER SUPPLY VIA G PIB INTERFACE..

1

1

3. CONNECTING POWER SUPPLY VIA RS232 INTERFACE 4

4.

INPUT AND OUTPUT QUEUE………………………………..

7

5. COMMANDS AND SYNTAX…………………………………. 7

6. DETAILS OF COMMAND REFERENCE…………………… 19

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

38

PROGRAMMER MANUAL

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1. INTRODUCTION

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

Interface selection and setup

The GPIB address can be changed in normal op eration condition. Press
[SHIFT] key and [LOCAL] key on the front panel, in which the last
transmitting interface settings will be displayed. Select interface and
press [ENTER], then select the baud rate (or GPIB address) and press
[ENTER] to confirm the setting by using the knobs. Finally, select “save”
and press [ENTER] to store the setup.

2. CONNECTING THE PROGRAMMABLE POWER

SUPPLY VIA GPIB INTERFACE

PROGRAMMER MANUAL

L4 (Listener) : The power supply becomes a listener

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

SR1 (Service Request) : The power su pply asserts the SRQ

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

RL1 (Remote/Local) : The power supply responds to both the

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

PP0 (Parallel Poll) : The power supply has no Parallel Poll

interface function.

DC1 (Device Clear) : The power supply has Device clear

capability to return the device to power
on status.

DT0 (Device Trigger) : The power supply has no Device Trigger

interface function.

C0 (Controller) : The power supply can not control other

devices.

The GPIB interface capabilities:

The GPIB interface of the programmable power supply correspond s 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 power supply can transmit multilane

messages across the GPIB.

AH1(Acceptor Handshake) : The power supply 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.

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Notes for GPIB installation

When the programmable power supply is set up with a GPIB system,
please check the following things:

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.

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PST & PSS & PSH SERIES PROGRAMMABLE POWER SUPPLY

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PROGRAMMER MANUAL

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 programmable power supply via GPIB interface.

The connections between power supply and computer are following:

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

the programmable power supply.

III. Turn on the programmable power supply.
IV. Turn on the computer.

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, serial number and
firmware version in the following format:

WK.TMPRO,PST-3202,A000000,FW1.00

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

PROGRAMMER MANUAL

3. CONNECTING THE PROGRAMMABLE POWER

SUPPLY VIA RS232 INTERFACE

The RS232 interface capabilit ies:

The RS232 interface provides a point-to-point conn ection between two
items of equipment such as a computer and the power supply. There are
some parameters you need to set on the both sides. Once you have set
these parameters, you can control the power supply through the RS232
interface.

z Baud rate: You can set rates of 1200, 2400, 4800 or 9600 b aud.
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 power supply is a DTE device with a 9-pin D-type shell RS232
connector located on the rear panel. Figure 1 shows the equipment of 9­pin connector (male) with its pin number assignments. Figure 2 shows
the wiring configuration for DB9 to DB9. When the p rogra mmab le pow er
supply is set up with a RS232 interface, please check the following
points:

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 or 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 equipment is connected to the

chassis ground of the external device.

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PST & PSS & PSH SERIES PROGRAMMABLE POWER SUPPLY

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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 dev ice as 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 instrumen t.

1. No connection

2. Receive Data (RxD) (input)

3. Transmit Data (TxD) (ou tput)

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 programmable power supply via RS232 inter face.

The connections between power supply and computer are as 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

programmable power supply.

III. Turn on th e progr ammab le power supply.
IV. Turn on the computer.

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The RS232 connection testin g

If you want to test whether the RS232 connection is working o r 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:

WK.TMPRO,PST-3202,A000000,FW1.00

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

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 programmable power supply 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

SCPI

Common Command & Queries

Syntax & Status Data Structure

Interface Function

AABBCCDD

SCPI

IEEE-488.2 IEEE-488.2

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

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 l ayer (10 int erf ace fun ctio ns to tall y).
At layer B, the syntax and data structure could be the e ssence 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 q ueries 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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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 has a hierarc hical structure tha t 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.

Root node

PROGRAMMER MANUAL

The command header is configured by 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 th e syntax of the co mmand, the < > s ymbols
are used for enclosing the par ameter type . For instance, the syntax of the
command in Figure 6 includes the Boolean parameter type.

Figure 4: Tree hierarchy

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Lower-level node

Leaf Node

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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PST & PSS & PSH SERIES PROGRAMMABLE POWER SUPPLY

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PROGRAMMER MANUAL

Table 1 defines the Boolean and other parameter types for the
programmable power supply.

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 Descript 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 (hexade ci mal 0A ) with END

message

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.

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 programmable power
supply 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 programmable
power supply. This flexibility, called friendly listening, saves
programming time and makes the command set easier to remember and
use.

Command Characters

The programmable power supplies are 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 characters. You must,
however, use at least one space between the parameter and the command
header

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 :CHANnel1:VOLTage 1.23
simply as :CHAN1:VOLT 1.23

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

Combining Commands

You can use a semicolon (;) to combine commands. But continuously
query command will cause message missing. For example:
CHAN1:VOLT ?;CURR ?

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:

:CHAN1:VOLT 1.23;:OUTP:COUP:TRAC 1
If the command that follows the semicolon has the same header path, you

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

:CHAN1:VOLT 12.34;CHAN1:CURR 1.55
is equal to
:CHAN1:VOLT 12.34;CURR 1.55
You can combine commands and queries into the same message. Note,

for example, the following comb ination :
:CHAN1:VOLT 12.34;VOLT ?

PROGRAMMER MANUAL

z

General Setting Commands

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

Table 2: General Setting Commands

Command Explanation

:CHANnel<x>:CURRent <NR2> ★1 Sets the value of current.
:CHANnel<x>:CURRent ? ★1 Return the value of current.

:CHANnel<x>:VOLTage <NR2> ★1 Sets the value of voltage.
:CHANnel<x>:VOLTage ? ★1 Return the value of voltage.

:CHANnel<x>:MEASure:CURRent ? ★1 Returns actual output current.
:CHANnel<x>:MEASure:VOLTage ? ★1 Returns actual output voltage.
:CHANnel<x>:PROTection:CURRent

<Boolean>

:CHANnel<x>:PROTection:CURRent ? ★1 Returns the state of the over-

:CHANnel<x>:PROTection:VOLTage
<NR2>

★1 Sets the overcurrent protection

(OCP) on or off.

current protection (OCP)
setting as either on or off.

★1 Sets the value of overvoltage

protection (OVP).

Synopsis of Commands

The tables in this section summarize the command of the programmable
power supply. These tables divide the commands into three functional
classifications:

z General Setting Commands
z Status Commands
z Miscellaneous Commands

The tables also provide a brief explanation of each command.

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:CHANnel<x>:PROTection:VOLTage ? ★1 Returns the overvoltage

protection (OVP) setting.

:OUTPut:COUPle:TRACking <NR1> ★2 Sets the output of the power

supply working on Series­tracking or Parallel-tracking or
independent mode.

:OUTPut:COUPle:TRACking ? ★2 Returns the output of the power

supply working mode.

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