Planet Finder Spectrograph


Data Reduction

PFS data may be reduced using a variety of different publicly available software packages. A PFS-specific raw data reduction package is not publicly available, nor is code for deriving radial velocities from the reduced data.


The PFS GUI was developed by Christoph Birk. See the information here or contact Christoph directly with questions.

Programmable Logic Controller (PLC) : Current version 2016-05-03

The PFS electronics are controlled by an AutomationDirect DirectLogic PLC. The PLC code and associated files, available in ZIP files below, were generated using AutomationDirect's DirectSOFT 5 application.

Version 2016-05-03 : This version includes control of the air heating system added on April 29, 2016. The system is enabled by default at PLC startup. The fan is turned on, powered by a 12VDC supply through a relay module with a series resistor in the electronics enclosure to reduce the fan voltage. Heating resistors are powered by the AC output module, but default to zero on system startup. The duty cycle is set by the meta controller.

Version 2012-08-12 : This version implements control of a resistor mounted next to the photomultiplier that turns on when the PMT is off in order to keep the heat output constant. In addition, the dewar heater control has changed to set a static AC output to the heating pads on the side of the dewar and a variable DC output to the heating pads on the back plate of the dewar. TDI exposure modes have been discontinued, and the GUI now keeps track of the PMT counts for the purpose of ending the exposure in Counts mode. The coprocessor is therefore no longer needed. It continues to run, but does not do anything. The first PFSGUI version that was used with this version of the PLC code was v1.4.

Version 2010-08-30 : Use with co-processor code version 0.9.0b and PFS GUI version 1.1. This version works with the serial PMT. Note that the ladder program stage for the PMT is relevant only to the new TTL PMT, except for the rung that controls the power to the PMT (through coil 206). This version of the code was being used for development in anticipation of the installation of the new TTL PMT, which is why that stage exists in it.

Electronics Enclosure Touch Screen : Current version 20110126

Version 2012-01-26

Version 2010-09-01: This version works with PLC code version 2010-09-01. It will also work with PLC code version 2010-08-30 except for the screen devoted to the PMT. The PMT screen was modified in anticipation of swapping the serial PMT for a TTL PMT. The old version of the touch screen code, relevant to the serial PMT, was not saved.

PLC Co-processor Module: No longer in use as of August 2012

Note: As of August 2012, the coprocessor no longer serves any active function. It remains in the PLC in case a need to revert exists in the future.

An AutomationDirect F2-CP128 co-processor module (manual) was used in the PFS PLC to communicate with serial devices. It runs a version of BASIC ( manual ). Interaction with the module requires use of AutomationDirect's "ABM Commander" application. Editing the BASIC code through this interface is cumbersome. Modifications to the code should be made offline using a text editor, and then the new code should be uploaded to the module.

Version 0.9.2, 1 September 2010: Repeat problems with the original serial PMT "freezing" (or, more likely, the co-processor hanging) led to a decision to replace the serial PMT with a TTL-output PMT. This was installed on 31 August 2010. The PLC CPU handles the TTL-PMT data now. The co-processor still communicates with the CCD actuator and performs calculations related to TDI control.

Version 0.9.0b, 1 March 2010: PFS originally contained two serial devices - a photomultipler tube (PMT) package and a linear actuator used to move the science CCD during time-delayed integration (TDI) exposures. This version of the code works when both of these devices are installed. Use with PLC code version 2010-08-30 and GUI version 1.1.

Last modified: 04 May 2016 05:22:09 am.