GitHub - bwachter/peaktech-psu

Peaktech PSU for Emacs

Overview

This is an Emacs mode to control the PeakTekch P 6070 - the protocol specification is available in the download section there, and a summary listed below.

The P 6172 and P 6173 should have the same protocol, and also work with this.

P 6075, P 6192 and P 6193 have two channels - adding those extra channels should be trivial, though I don’t have hardware to test.

Data from the power supply is polled every peaktech-psu-poll-interval seconds (default: 1). This will refresh the display, and call any hooks defined in peaktech-psu-measurement-hook - which can be used for collecting statistics.

A sample hook to plot voltage and current over time via eplot is included in peaktech-psu-eplot.el, and shown in the screenshot above. It logs data as CSV, so pcsv is also required.

Protocol summary

This is mostly copied from the PeakTech documentation, added here for ease of access.

USB-serial, 9600 8N1.

All command payloads consist of a series of two-digit hexadecimal values, forming a core data sequence. Before transmission, this sequence must be validated using a CRC-16/MODBUS algorithm in LSB-first format. After CRC calculation, the resulting checksum (also referred to as the check code) is appended to the core data sequence, followed by a fixed end code (0xFD). The final structure forms the complete data frame, which we refer to as a “command”.

Accordingly, all values in amps or volts inside a payload are also encoded in hexadecimal format. Examples can be found in the relevant sections under “Command Reference” below.

Command-Formation Example

Initial payload: F7 02 0A 1E 01 00 01

Payload with the CRC checksum and the end code appended: F7 02 0A 1E 01 00 01 92 04 FD (A valid command that is ready to be transmitted)

92 04 is the calculated CRC checksum of the payload above (CRC-16/MODBUS, LSB-first) FD is the end code

Command reference

Output control

Set output to ON:

Set output to OFF:

Read all values

Response frame

Data fiields:

Setting voltage

The value in volts must be converted from decimal to hexadecimal. For example, 5.14 V corresponds to ‘02 02’ in hexadecimal.

Setting current

The value in amperes must be converted from decimal to hexadecimal. For example, 0.514 A corresponds to ‘02 02’ in hexadecimal.