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.

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

Meters:

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

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.

GW Instek's below series of products have the option of Modbus,

• DC power supplies：including the PSW、PSU series and the PFR series.
• AC/DC power supplies：ASR-2000/3000/6000 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.

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.

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.

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.

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.

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.