Isolated USB 4-20mA Current Loop Receiver – Kappa4420USB

Name: Isolated USB 4-20mA Current Loop Receiver - Kappa4420USB
SKU: Kappa4420USB
Price: 20.00 USD
Availability: OutOfStock

Isolated USB 4-20mA Current Loop Receiver - Kappa4420USB - Image 2

Isolated USB 4-20mA Current Loop Receiver - Kappa4420USB - Image 3

Isolated USB 4-20mA receiver based on the IS4420-M1 module. Read the loop current from your PC without writing any firmware.

Current Loop Input:
– Measuring range: 0 mA to 21.5 mA
– Resolution: 0.01 mA and 0.1 % of the 4-20mA span
– 2-wire and 3-wire transmitters
– Factory calibrated at 4 mA and 20 mA

PC Interface:
– USB Micro-B, virtual COM port
– 115200 baud, 8N1, no flow control
– ASCII text readings, about ten per second
– Free IS4420WIN software for Windows

Isolation:
– Galvanic isolation between USB and current loop

Out of stock

SKU: Kappa4420USB

Isolated USB 4-20mA Receiver for Your PC

The Kappa4420USB is an isolated USB 4-20mA receiver based on the IS4420-M1 I2C 4-20mA current loop receiver module. The board sends the IS4420-M1 readings straight to your PC through a virtual COM port, so you can read a current loop without writing any firmware. There are no commands to send: open the COM port and the readings arrive.

Use this USB 4-20mA receiver to evaluate the IS4420-M1 before integrating it into your own product. It also works as a ready-to-use current loop meter on your bench or production line.

Applications

Sensor reading: read temperature, pressure, level and flow transmitters from your PC.
Transmitter testing: check and calibrate 4-20mA transmitters.
Loop commissioning: verify the loop current while you install and troubleshoot PLC and field wiring.
Data logging: record the loop current over time with the IS4420WIN software.
Test automation: read the loop from your own software in laboratory and production tests.

How the USB 4-20mA Receiver Works

The loop current flows through the 150 Ω shunt of the IS4420-M1, which measures it about ten times per second. After each measurement, the IS4420-M1 sends one line of ASCII text with the loop current in mA, its percentage of the 4-20mA span, the module temperature, the model and the module revision. The Kappa4420USB passes this line to the PC through a PL2303GL USB-to-UART bridge, so the PC sees the board as a standard serial (COM) port.

Galvanic isolation separates the USB side from the current loop side. As a result, the PC ground and the current loop ground stay separate. This prevents ground loops and protects your PC from the current loop wiring.

Precise, Stable Readings

0.01 mA resolution, plus the percentage of the 4-20mA span with 0.1 % resolution: 4 mA is 0 % and 20 mA is 100 %.
Fault levels stay visible: readings below 4 mA give negative percentages, and readings above 20 mA go over 100 %.
Mains ripple rejection: each measurement averages 100 ms, exactly 5 periods of 50 Hz and 6 of 60 Hz.
Factory calibrated at 4 mA and 20 mA.
Clear error reporting: the line shows EOVER above the measuring range and ERROR when there is no valid measurement, instead of a wrong value.

Works with Your Tools

The board works on Windows, Linux and macOS, with standard serial settings (115200 baud, 8N1). Use IS4420WIN, the free INACKS software for Windows, to display the loop current in mA and % and log the results. Any serial terminal program also shows the readings. Your own software only needs to open the COM port and read the lines: every line has a fixed length, and every value is always in the same position.

Hardware Features

IS4420-M1 4-20mA current loop receiver module, factory calibrated.
USB Micro-B connector with a PL2303GL USB-to-UART bridge.
Galvanic isolation between the USB side and the current loop side.
Measuring range from 0 mA to 21.5 mA, for 2-wire and 3-wire transmitters.
Power: the board is isolated, so it needs both the USB power and the current loop power supply, as any current loop configuration does.

Quick Start with the USB 4-20mA Receiver

Wire the transmitter and the current loop power supply to the Kappa4420USB, as shown in the user manual.
Then, connect the Kappa4420USB to your PC with a USB cable and switch on the current loop power supply.
Open IS4420WIN, or open the COM port at 115200 baud, 8N1, with a serial terminal program.
Finally, read the loop current: a new line arrives about ten times per second.

For the wiring details and the complete description of the data format, see the Kappa4420USB User Manual (ISDOC158). In addition, the IS4420-M1 datasheet (ISDOC146) covers the detailed specifications of the module.

This company and the products provided herein are developed independently and are not affiliated with, endorsed by, or associated with any official protocol or standardization entity. All trademarks, names, and references to specific protocols remain the property of their respective owners.

(This product includes the Kappa4420USB. The current loop power supply and the transmitter are not included.)

Documentation

Q: What is the Kappa4420USB used for?

A: To read a 4-20mA current loop from a PC. Use it to evaluate the IS4420-M1 module before integrating it into your own design, or as a PC-based current loop meter to read sensors and transmitters, test and calibrate transmitters, commission loops, log measurements, or automate laboratory and production tests.

Q: Do I need to write any firmware or install any libraries?

A: No. The Kappa4420USB sends the IS4420-M1 readings to the PC on its own, as lines of ASCII text on a virtual COM port. There are no commands to send: open the COM port with the free IS4420WIN software, a serial terminal program or your own software, and read the lines.

Q: What data does it send?

A: One line of ASCII text about every 103 ms, with:

The loop current in mA, with two decimals.
The percentage of the 4-20mA span, with one decimal: 4 mA is 0 % and 20 mA is 100 %.
The temperature inside the IS4420-M1, in whole °C.
The model and the module revision.

Every line has a fixed length, and every value is always in the same position. Above the measuring range, the current and the percentage show EOVER, and when there is no valid measurement they show ERROR.

Q: What current range can it read?

A: From 0 mA to 21.5 mA. This covers the standard 4-20mA range, plus the levels below 4 mA and above 20 mA that many transmitters use to signal faults. Currents above 21.5 mA are reported as over-range.

Q: What resolution does it offer, and how often does it measure?

A: The current comes with 0.01 mA resolution, and the percentage of the 4-20mA span with 0.1 % resolution. The IS4420-M1 averages each measurement over 100 ms, exactly 5 periods of 50 Hz and 6 of 60 Hz, so mains ripple averages out. A new reading arrives about ten times per second.

Q: Is it calibrated?

A: Yes. Every IS4420-M1 is calibrated at the factory at 4 mA and 20 mA, and every reading is corrected with these two points before it is sent. No calibration is required to use the board.

Q: Which transmitters can I connect?

A: 2-wire and 3-wire 4-20mA transmitters, the most common types. You can also read 4-wire transmitters, paying attention to how their grounds are connected.

Q: Is the USB port isolated from the current loop?

A: Yes. Galvanic isolation separates the USB side from the current loop side. The PC ground and the current loop ground are not connected, which prevents ground loops and protects your PC from the current loop wiring.

Q: Which operating systems are supported?

A: Windows, Linux and macOS. The Kappa4420USB uses a Prolific PL2303GL USB-to-UART bridge, which the PC sees as a standard serial port. On Windows, the driver is usually installed automatically. Recent Linux kernels include the pl2303 driver. On macOS, install the PL2303 driver from the Prolific website if the port does not appear. The free IS4420WIN software runs on Windows.

Q: Can I read it from my own software?

A: Yes. Any software that can open a serial port can read the Kappa4420USB: open the port at 115200 baud, 8N1, and read the lines as they arrive.

Q: What is included?

A: The Kappa4420USB board. The current loop power supply and the transmitter are not included.

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