AUSTRALIAN NATIONAL UNIVERSITY System Design Note 11.12 Created: 12 September 2001 Last modified: 12 September 2001

EPICS DATA LOGGER FOR THE NIFS TEMPERATURE CONTROL SYSTEM

Mark Jarnyk

Research School of Astronomy and Astrophysics

Institute of Advanced Studies

Australian National University

Revision History

Revision No.	Author & Date	Approval & Date	Description
Revision 1	Mark Jarnyk 11 September 2001	Peter Young 11 September 2001	Original document.

Contents

1 Purpose. 1

2 Applicable Documents. 2

3 Introduction. 2

4 Use. 2

5 Technical Details. 4

Appendix A: List of Figures. 4

1 Purpose

The purpose of this document is to describe the use of the data logger written for the Gemini Near-infrared Integral Field Spectrograph (NIFS) temperature control system.

2 Applicable Documents

Document ID	Source	Title
	Lake Shore	User’s Manual Model 340 Temperature Controller
	OMEGA Engineering Inc.	CYC3211, CYC3212, CYC3214 Cryogenic Temperature Controller – Operator’s Manual
	OMEGA Engineering Inc.	Operator’s Manual Model CYD201 and CYD208 Digital Thermometer

3 Introduction

The Solaris program, tlog, is used to log all data coming from the EPICS temperature control system of the Gemini Near-infrared Integral Field Spectrograph (NIFS). It uses channel access to retrieve values from the engineering database and writes them to standard output.

4 Use

The format of the command is

tlog sample_time

where sample_time can be specified in seconds, minutes or hours by suffixing the number with “s”, “m” or “h” respectively. If no suffix is present, then the units are seconds. Thus, the commands:

tlog 300

tlog 300s

tlog 5m

are equivalent.

To use this command, first ensure that you are “logged in”, as with other NIFS programs. To do this, change to the NIFS root directory and type:

source nifsLogin

This sets up the environment which tlog and other programs use. To run tlog change to the ENG/bin/solaris directory. To log data every five minutes, type in:

./tlog 300

The data is written to standard output. If you wish to write it to a file, then simply use redirection, thus:

./tlog 300 > datafile &

The & puts the process into the background. tlog is terminated by typing in

./tlog stop

tlog dumps all the values from the temperature control aspects of the database. At present, this consists of fifty-seven channels, so the resulting log has a lot of data in it. The file is not meant for human viewing, but rather is intended to be loaded into a plotting program or spreadsheet. Each column is tab-delimited. Lslog was purposely designed such that individual channels could not be switched off. This was done, such that there would always be a full record of all germane information to a cool-down, making retrospective diagnosis of problems easier. This is especially important in a system like NIFS that can take a week to cool down. The large amount of resulting data should not be a problem, since it can be manipulated easily by plotting programs and text manipulators such as awk.

Table 1: Parameters recorded by tlog.

Column	Parameter	Units
1	time since logging started	seconds
2	Temperature at top of strap	K
3	Temperature at bottom of strap	K
4	Getter temperature	K
5	Temperature at edge of cold work surface	K
6	spare 1
7	spare 2
8	spare 3
9	spare 4
	Cold work surface
10	Temperature	K
11	Set point	K
12	Heat	%
13	Proportional gain
14	Integral gain
15	Differential gain
16	Range
17	Tune
	OIWFS
18	Temperature	K
19	Set point	K
20	Heat	%
21	Proportional gain
22	Integral gain
23	Differential gain
24	Range
25	Tune
	Detector
26	Temperature	K
27	Set point	K
28	Heat	%
29	Proportional gain
30	Integral gain
31	Differential gain
32	Range
33	Tune
	Detector Housing
34	Temperature	K
35	Set point	K
36	Heat	%
37	Proportional gain
38	Integral gain
39	Differential gain
40	Range
41	Tune
	For loop controlling temperature on detector
42	output: percentage of output of an analog output	%
43	polarity: Specifies whether the analog output is bipolar or positive only.
44	mode : specifies data the analog output monitors: 0 = off, 1 = input, 2 = manual, 3 = loop.
45	input: Specifies which input to monitor if mode = 2.
46	Specifies input data: 1 = Kelvin, 2 = Celsius, 3 = sensor units, 4 = linear equation.
47	high: If mode is 1, then this is the data at which the analog output represents +100% of output.
48	If mode is 1, then this is the data at which the analog output represents -100% of output if bipolar, or 0% output if positive output only.
49	manual: If mode is 2, this parameter is the output of the analog output.
	For loop controlling temperature on detector housing
50	output: percentage of output of an analog output	%
51	polarity: Specifies whether the analog output is bipolar or positive only.
52	mode : specifies data the analog output monitors: 0 = off, 1 = input, 2 = manual, 3 = loop.
53	input: Specifies which input to monitor if mode = 2.
54	Specifies input data: 1 = Kelvin, 2 = Celsius, 3 = sensor units, 4 = linear equation.
55	high: If mode is 1, then this is the data at which the analog output represents +100% of output.
56	If mode is 1, then this is the data at which the analog output represents -100% of output if bipolar, or 0% output if positive output only.
57	manual: If mode is 2, this parameter is the output of the analog output.

5 Technical Details

tlog is a Bourne shell script acting as a wrapper around coollog, a C program using the ezca channel access library. Whilst this library is not very efficient, it is being used in a program that will typically sleep for 5 minutes between samples, so efficiency is not needed. tlog saves coollog’s PID in the file ENG/bin/solaris/.tlog.pid, so that it can kill it later when instructed to via the “stop” command.

Appendix A: List of Figures

Figure 1

figure.gif