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Q1 gw_product_detail_bar.png gw_product_detail_bar.png What are SCPI, VISA, IVI, LXI commonly used in instrument control?


SCPI is the abbreviation of Standard Commands for Programmable Instruments. SCPI defines the syntax and commands for controlling programmable test and measurement instruments. Through SCPI, the command can be simplified such as Measure command can be simplified as MEAS.


VISA is the abbreviation of Virtual Instrument Software Architecture. After executing the VISA program, VISA will scan whether all computer interfaces are connected to the instrument. Through the VISA program as an intermediary, the execution of instrument control can be accelerated.


IVI is the abbreviation of Interchangeable Virtual Instrument.


LXI is the abbreviation of LAN eXtensions for Instrumentation. It is an alliance established by the electronic instrument industry in 2004. Its purpose is to simplify the integration of test systems through the local area network LAN.

Q2 gw_product_detail_bar.png gw_product_detail_bar.png For engineers who are not familiar with any programming language, is there any other way to perform remote control of the instrument?


PLC (Programmable Logic Controller) has the functions of 0~10Vdc analog output and reading. It can be used with GW Instek's instruments with Analog Control to remotely control the output of the instrument through DC voltage.


Power Suppliers:


The PFR series, the PLR series, the PSW series, the PSU series, the PSB series


Electronic loads:


The PEL-3000 series


Dielectric withstanding voltage testers also have similar Signal I/O for similar control


The GPT9800/9900/12000/15000 series




The GDM-8352, GDM-9061, GDM-8261A, GOM series, LCR-6000/8000


Q3 gw_product_detail_bar.png gw_product_detail_bar.png Problems related to connecting the computer with the Linux operating system to the instrument using USB

Question 1: Do I need to install a USB driver?


Answer: The CDC-ACM for USB supports all current versions of Linux operating systems. In this case, there is no need to install the USB driver. Unless it is a very old version, you need to build it yourself.


Note 1: CDC (Communication Device Class)

Note 2: ACM (Abstract Control Model)


Question 2: Which series of products from GW Instek support USB CDC and can work in Linux without the need to install USB drivers?


Answer: The PPX series, PFR-100 series, PSU series, PSW series DC power supplies, ASR series AC/DC power sources, PEL-2000/3000 series electronic loads, and GDS series oscilloscopes with USB support.

Q4 gw_product_detail_bar.png gw_product_detail_bar.png Which instruments of GW Instek support MODBUS communications protocol?


GW Instek's below series of power supplies have the option of Modbus, including the PSW、PSU series and the PFR series.


The following reference is from Wikipedia


Modbus is a serial communication protocol that was published in 1979 by Modicon Corporation (now Schneider Electric) for communication using Programmable Logic Controllers (PLCs).


Modbus has become the de facto industry standard for communication protocols in the industrial field and is now a common method of connection between industrial electronic devices.

Q5 gw_product_detail_bar.png gw_product_detail_bar.png Check steps for the instrument not being able to connect to the computer

The instrument should be connected to the computer, and the components include the computer, the interface cable, and the instrument. So the check steps naturally contain these three components.


Step 1:

Confirm the operating system (OS) and application software of the computer. If VISA is used as the instrument connection detection, it should be noted that the earlier operating systems are not compatible with the VISAs of the two companies.


For example, installing NI VISA and other Instrument company's VISA will cause conflicts and cannot be used. Interface driver installation. Installation of instrument application software. If a GPIB-to-USB adapter is used, the driver and settings of the adapter should also be sound.


Step 2:

Interface cable, if RS-232 connection is used, a Null Modem jumper is required (see the manual for the jumper diagram). If LAN connection is used, the computer and the instrument are directly connected, and attention must be paid to the network chip of the old computer cannot automatically jump, and network jumpers must be specially made. GPIB and USB cables do not need special handling.


Step 3:

Instrument settings, GPIB needs to set Address, LAN connection needs to set specified IP and mask, and IP can be obtained automatically through DHCP, RS-232/485 needs to set the same transmission rate and other settings, please use USB and go to the official website to join the membership and download the driver.


Step 4:

Use a program (such as NI Max) to issue the *IDN? command to the instrument (note that there must be a terminator, such as CR or LF). If the instrument ID can be returned, it means the connection is successful. If the connection is made through an Ethernet network (LAN), if the instrument supports the function of a web browser, you can directly enter the IP of the instrument in the browser to confirm whether the connection is normal.


Q6 gw_product_detail_bar.png gw_product_detail_bar.png Is the programming code of the ASR-2000 series compatible with that of APS-1102A?


Since the ASR-2000 series is designed with a new architecture and provides new functions, the programming code is not compatible with that of APS-1102A.

Q7 gw_product_detail_bar.png gw_product_detail_bar.png What is the speed of the PSW series power supply when connecting to the computer via USB?


The PSW series power supply is connected to the computer via USB. The speed of voltage or current setting and voltage or current readback is about 100ms.

Q8 gw_product_detail_bar.png gw_product_detail_bar.png What is the function of the local key?

If you want to disable the remote control mode from PC please follow as below step: LOCAL(GPIB/RS-232) : Clear the Remote Control mode and use the panel control mode instead. Press [SHIFT][GPIB/RS-232] to GPIB or RS-232 setting selection.

Q9 gw_product_detail_bar.png gw_product_detail_bar.png Using GPIB chips shortage in 2022 to talk about the past and present of GPIB

GPIB is the abbreviation of General Purpose Interface Bus. Her past was HPIB (Hewlett-Packard Interface Bus). Since it was developed by the American instrument manufacturer Hewlett-Packard (Hewlett-Packard abbreviated as HP) in the late 1960s (about 1965) to control instruments produced by HP Technologies. Compared with another long-established interface RS-232 (the earliest version was released in 1962), HPIB has the advantage of parallel connection.


In 1975, the IEEE International Institute of Electrical and Electronics Engineers released the IEEE488 standard based on HPIB. Since then, HPIB has become The well-known GPIB, the GPIB card of ISA Bus was the most widely used in the era of IBM PC. NI (National Instruments), which was established in 1976, and its virtual instrument promotion automation measurement ushered in a brilliant application era for GPIB.


Even with the continuous advancement of computers and the introduction of new interfaces, GPIB, the old soul of the instrument control industry, still stands firmly. After the popularity of notebook computers, PCMCIA to GPIB interface cards and GPIB to USB adapters were launched for GPIB.


In response to the supply chain disruption of the GPIB chip and the high price, the automated test should immediately switch the control interface to respond


In 2022, due to the shortage of raw materials caused by the pandemic, NI's GPIB ASIC is seriously out of stock. The cheapest chip NAT7210, which was queried on the NI website on June 21, 2022, was as high as NT$7,900, and the most expensive TNT500X was priced at NT$39,300. The GPIB interface has become an unusable (long delivery time) or unaffordable (expensive) interface.


In addition to the GPIB ASIC chip, another way to implement GPIB is to plan the FPGA in the instrument as a GPIB IP Core. For instruments that use FPGA, such as digital oscilloscopes and arbitrary waveform generators, the possibility of GPIB can continue to be provided. But for instruments using less FPGA such as power supplies, it is a luxury to provide a GPIB interface in the future. Power supplies are almost the heart of any automated measurement system.


Therefore, we would like to call on to electronic engineers engaged in automated measurement to take precautions by turning the interface of the instrument control to LAN or USB as soon as possible. After all, GPIB seems to have reached the stage of retiring after winning merit and stepping into the history.

Q10 gw_product_detail_bar.png gw_product_detail_bar.png AWG (American wire gauge)
AWG Gauge Conduct or Diameter mm Ohms per km Max amps for chassis wiring
0000 11.684 0.161 380.000
000 10.404 0.203 328.000
00 9.266 0.256 283.000
0 8.252 0.322 245.000
1 7.348 0.406 211.000
2 6.543 0.513 181.000
3 5.827 0.646 158.000
4 5.189 0.815 135.000
5 4.620 1.028 118.000
6 4.115 1.296 101.000
7 3.665 1.634 89.000
8 3.264 2.061 73.000
9 2.906 2.598 64.000
10 2.588 3.276 55.000
11 2.304 4.133 47.000
12 2.052 5.209 41.000
13 1.829 6.570 35.000
14 1.628 8.282 32.000
15 1.450 10.444 28.000
16 1.290 13.172  22.000 
17 1.151 16.610  19.000 
18 1.024  20.943  16.000 
19 0.912  26.407  14.000 
20 0.813  33.292  11.000 
21 0.724  41.984  9.000