High Precision Temperature Sensors

Table of Contents:

Page Status

Date	Initials	Change
June 24, 2021	SG	Changed page name from “Lakeshore 224-12” to match convention used with other device pages
May 10, 2021	SG	First complete draft, ready for Will and Brad

Relevant Devices

Description	Qty	Source	Part Number
High Precision Temperature Sensors	1	Lakeshore	224-12
Cryostat Temperature Sensors	1	Lakeshore	224-12

NOTE: we have two identical devices. The only difference in the control software between the two will be the look-up table which maps the Lakeshore sensor input names (i.e. ‘C1’) to physical sensor locations within KPF (i.e. ‘Echelle’).

Relevant Functional Block Diagram

Both Lakeshores will be set up the same, with sensors placed at (or within) the vacuum chamber.

Software Actions

	Action	Notes
1	Read 12 temperature values	Values reported as telemetry (see below)
2
3

Required Adjustable Settings

Setting	When Needed			Notes
	Build	Observing	Maintenance
Temperature measurement frequency	Yes	No	Maybe

Device Set-up Parameters

Annotated command list with KPF settings.

Required Telemetry

	Parameter	Report Frequency	Purpose
1	Input A Temperature [deg C]	Once every 5 sec [TBC]	Environmental monitoring
2	Input B Temperature [deg C]
3	Input C1 Temperature [deg C]
4	Input C2 Temperature [deg C]
5	Input C3 Temperature [deg C]
6	Input C4 Temperature [deg C]
7	Input C5 Temperature [deg C]
8	Input D1 Temperature [deg C]
9	Input D2 Temperature [deg C]
10	Input D3 Temperature [deg C]
11	Input D4 Temperature [deg C]
12	Input D5 Temperature [deg C]

Lakeshore Input Names/KPF Location Look-up Tables

Green Lakeshore

	Lakeshore Input	KPF Location
1	A	Green Cryostat Individual Locations TBD
2	B
3	C1
4	C2
5	C3
6	C4
7	C5
8	D1
9	D2	Spectrometer Individual Locations TBD
10	D3
11	D4
12	D5

Red Lakeshore

	Lakeshore Input	KPF Location
1	A	Red Cryostat Individual Locations TBD
2	B
3	C1
4	C2
5	C3
6	C4
7	C5
8	D1
9	D2	Spectrometer Individual Locations TBD
10	D3
11	D4
12	D5

Required Alarms

	Parameter	Threshold	Notes
1
2

Relevant Datasheets & Manuals

Description

File

Source

1

Device Manual

https://www.lakeshore.com/products/categories/downloads/temperature-products/cryogenic-temperature-monitors/model-224-temperature-monitor

2

Rack Mounting Instructions

Relevant Software

	Description	File	Source
1	Python code that sets up a Lakeshore 224 with KPF settings.		Written by S. Gibson for tests at SSL.
2

Dispatcher Implementation

Currently this is part of the kpfmet service. That service has multiple dispatchers, each is noted by a dispatcher number or $(DISPNUM)

Each Lakeshore has a unique name, noted as $(NAME). Currently the names are green and red but that can easily change. That name is used to denote details about the connections.

Finally, each sensor has a unique name, noted as $(sensor). That name is set by the configuration file. The keyword for the sensor is set by the sensor name. The units, data type, and display format are also all defined in the configuration file.

Keyword	Value	Type
$(NAME)_SERIAL	LSA2BFB/OCD2BFB/OCC2BFB Serial number of device read at connection.	String - read only
$(NAME)_REV	1.2 Version of device, read at connection	String - read only
$(sensor_name)	-273.15	Read only value from the sensor. The type, units, and format is determined by the configuration file (see below)
DISP$(DISPNUM)STA	0 - Ready 1 - Initializing 2 - Shutting down 3 - Connecting 4 - Not connected	Read only enumerated list gives status of the dispatcher. Ready means connected to the device. Initializing occurs at start up, shutting down when exiting, connecting when connecting and not connected when the connection to the Lakeshore is lost.
DISP$(DISPNUM)STOP	0 - Go 1 - Stop	Boolean that is writable, 1 means that the dispatcher exits.
DISP$(DISPNUM)CONN	IP address and port separated by colon	Read only string set in configuration file.
DISP$(DISPNUM)DEV	Device name	Read only string set in configuration file.
Other DISP keywords	last request, memory, clock, message and error	The standard dispatcher keywords.

Configuration File

Note, beyond the blocks device and dispatcher each sensor needs its own block. That block named by the sensor name, so, A, B, C1, etc.

Configuration	Value	Explanation
address	192.168.23.181	IP address of the Lakeshore
port	7777	port for connecting to the Lakeshore
poll_time	5	Time in seconds between queries
model	MODEL224	Model number for the device, must in the return string when the model is queried
name	green	Prefix of name, corresponds to which Lakeshore (could be removed)
dispnum	2	Dispatcher number.
name	sensor	Name of the sensor, must be in a block labeled by the internal sensor name (e.g., A, B, C2, etc.)
type	double	The data type of the value
format	%.3f	The ASCII format used for showing the data via KTL. The full data as returned by the device will be stored in the binary format.
unit	deg C	The units of the temperature. The options that actually make sense are deg C and deg K. There is no enforcement of that here but this only impacts the displayed values, it does not change the query made to the device (which can be K or C.)