Micronor FOTEMP MINI User manual

© COPYRIGHT 2022, MICRONOR SENSORS INC.
VENTURA, CA, USA
For Sales & Support in North America:
MICRONOR SENSORS INC.
2085 Sperry Ave, Suite A-1
Ventura, CA 93003 USA
[phone]
[e-mail]
www.micronor.com
HQ and Worldwide Sales & Support:
WEIDMANN TECHNOLOGIES DEUTSCHLAND GMBH
Washingtonstrasse 16
D-01139, Dresden
Germany
[phone]
[e-mail]
www.weidmann-optocon.com
Notice of Proprietary Rights
The design concepts and engineering details embodied in this manual, are the property of MICRONOR SENSORS and WEIDMANN
TECHNOLOGIES, and to be maintained in strict confidence; no element or detail of this manual is to be spuriously used, nor
disclosed, without the express written permission of MICRONOR SENSORS. All rights are reserved. No part of this publication
may be reproduced, stored in a retrieval system, or transmitted in any form or any means, electronic, mechanical, photocopying,
recording, or otherwise, without prior written permission from MICRONOR SENSORS.
FOTEMP MINI
OEM Signal Conditioner
User Manual
Document: 98-OPTC-26
Revision A dated 08-Sept-2022

MICRONOR SENSORS FOTEMP MINI OEM Signal Conditioner
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Revision History
Revision
Date
Notes
A
08-Sept-2022
Initial Release
Specifications are subject to change without notice

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Table of Contents
Revision History....................................................................................................... 2
1. Product Description............................................................................................................ 4
2. Initial Preparation............................................................................................................... 6
2.1 Unpacking and Inspection ............................................................................... 6
2.2 Damage in Shipment ....................................................................................... 6
2.3 Standard Contents ........................................................................................... 6
2.4 Warranty Information ....................................................................................... 7
3. Installation and Operation ................................................................................................. 8
3.1 Mounting the Unit............................................................................................. 8
3.2 Electrical Connections to the Unit................................................................... 9
3.3 Connecting the TS Temperature Probe.........................................................10
3.4 System Start-Up..............................................................................................10
4. Serial Communications.................................................................................................... 11
4.1 Introduction to UART Operation and Data Frame ........................................11
4.2 FOTEMP ASCII Serial Protocol........................................................................12
4.3 Communicating via FOTEMP-Assistant .........................................................13
4.4 Direct Serial Communications via PuTTY Terminal Emulator......................14
4.5 Sample Arduino Program...............................................................................15
5. FOTEMP MINI Specifications ........................................................................................... 16
6. FOTEMP MINI Theory of Operation.................................................................................. 17
7. FOTEMP MINI Reference Drawing................................................................................... 18
List of Figures
Figure 1. The SFF Weidmann FOTEMP MINI OEM Signal Conditioner........................ 4
Figure 2. How to identify Versions 1 and 2 of the FOTEMP MINI Signal Conditioner 8
Figure 3. Location of FOTEMP MINI Mounting Holes................................................... 8
Figure 4. Location of Power Supply and Serial Interface Connections ...................... 9
Figure 5. How TS Probe is connected to FOTEMP MINI ............................................10
Figure 6. UART Data Frame used by FOTEMP System ..............................................11
Figure 7. Setting Serial Port Settings via Device Manager .......................................13
Figure 8. Example of FOTEMP MINI Serial Communications Dialog using PuTTY...15
Figure 9. Sample Arduino Program.............................................................................15
Figure 10. FOTEMP MINI Theory of Operation ...........................................................17
Figure 11. Advantages of GaAs Fiber Optic Thermometry versus Thermocouples .17
List of Tables
Table 1. FOTEMP ASCII Command List ....................................................................12

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1. Product Description
The FOTEMP MINI (aka FTM) is a small form factor (SFF) OEM PCB interface module designed
for low cost insertion of high performance GaAs-based fiber optic temperature sensing
technology into OEM applications where common electrical temperature sensors and
thermocouples cannot be used. The SFF profile is ideal for embedded medical, life science
and energy applications such as:
•MRI, requires immunity to magnetic fields
•CT, requires non-metallic design and minimal contrast
•Switchgear and Transformers, requires electrical isolation and immunity to electrical
fields
Figure 1. The SFF Weidmann FOTEMP MINI OEM Signal Conditioner
The FOTEMP MINI is compatible with all TS series high precision GaAs fiber optic
temperature probes. The sensors are entirely non-metallic and electrically passive, providing
immunity to EMI, RFI, MR, microwaves and radiation is required.
Features
•Smallest form factor, single channel solution
•Purposely designed for embedded instrument applications
•3.3V-TTL interface for direct connection to Microcontroller UART serial port
•Easy to interface ASCII protocol
•Operates from 7-12V power
•0.1°K resolution
•Operating temperature: -20°C to +60°C
•Measurement range: -200°C to +300°C (depends on TS sensor used and Calibration
option)

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Applications
•For embedded instrument applications
•EMI, RFI and microwave environments
•High voltage environments
•Harsh and hazardous environments
•Nuclear environments
•Aerospace applications
•Process monitoring
•Medical and imaging applications (MRI)

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2. Initial Preparation
2.1 Unpacking and Inspection
Since the FOTEMP MINI is an electronic printed circuit board, the user should use ESD
protection when handling the module. THE FOTEMP MINI is shipped in an ESD protective
pouch.
When received, the shipping carton should contain the following items listed below. Account
for and inspect each item before the carton is discarded. In the event of a damaged
instrument, contact your near Weidmann Technologies representative. Please retain the
shipping container in case reshipment is required.
2.2 Damage in Shipment
If you receive a damaged instrument, you should:
•Report the damage to your shipper immediately.
•Inform local Weidmann Technologies representative or HQ.
•Save all shipping cartons.
Failure to follow this procedure may affect your claim for compensation.
2.3 Standard Contents
FOTEMP MINI OEM Signal Conditioner:
•FOTEMP MINI board with ST Pigtail (use ESD protection when handling)
•ST Bulkhead Adapter
•Weidmann Technologies (Factory) Calibration Report
•Micronor Sensors One-Point Calibration Report (if ordered with different TS sensor
than used for Factory Calibration)
•FOTEMP Resource USB Memory Stick containing copy of Technical Documentation
and FOTEMP-Assistant Software
TS series GaAs Fiber (Optic Temperature Probe)
•TS model as ordered and paired (calibrated) with above FOTEMP MINI

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2.4 Warranty Information
Warranty
WEIDMANN TECHNOLOGIES warrants this product to be free from defects in material and
workmanship for a period of 1 (one) year from date of shipment. During the warranty period
we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your WEIDMANN TECHNOLOGIES local representative
or WEIDMANN TECNOLOGIES headquarters. You will be given prompt assistance and return
instructions. Send the instrument, transportation prepaid, to the indicated service facility.
Repairs will be made and the instrument returned transportation prepaid. Repaired
products are warranted for the balance of the original warranty period, or at least 90 days.
Limitations of Warranty
This warranty does not apply to defects resulting from unauthorized modification or misuse
of any product or part. This warranty also does not apply to Fiber Optic Connector interfaces,
fuses or AC line cords. This warranty is in lieu of all other warranties, expressed or implied,
including any implied warranty of merchantability of fitness for a particular use. Neither
WEIDMANN TECHNOLOGIES nor MICRONOR SENSORS shall not be liable for any indirect,
special or consequent damages.
For North American Sales & Support:
Micronor Sensors, Inc. Tel [phone]
2085 Sperry Ave, Suite A-1 Email sales@micronor,com
Ventura, CA 93003 URL www.micronor.com
USA
HQ and Worldwide Sales & Support:
Weidmann Technologies Deutschland GmbH Tel [phone]
Washingtonstrasse 16 Email [e-mail]
D-01139, Dresden URL www.weidmann-optocon.com
GERMANY

MICRONOR SENSORS FOTEMP MINI OEM Signal Conditioner
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3. Installation and Operation
3.1 Mounting the Unit
As shown in Figure 1 below, there are two versions of the FOTEMP MINI OEM Controller
which differ by which side the various internal and external pin connectors are mounted.
FOTEMP MINI Version “1”
FOTEMP MINI Version “2”
Pin connectors for Power Supply and Serial
Port are located on front of board.
Pin connectors for Power Supply and Serial
Port are located on back (trace) side.
Figure 2. How to identify Versions 1 and 2 of the FOTEMP MINI Signal Conditioner
In either case, the mounting holes are in the same location as shown in Figure 3. Use
appropriately sized stand offs and allow adequate clearance for all wiring and components.
Figure 3. Location of FOTEMP MINI Mounting Holes

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3.2 Electrical Connections to the Unit
As shown in Figure 4, the FOTEMP MINI requires only Power Supply (7-12V DC) and Serial
Interface connections.
Electrical Connections viewed
from Component Side
Electrical Connections Viewed
from Back (Trace) Side
Figure 4. Location of Power Supply and Serial Interface Connections
IMPORTANT NOTE
Your Microcontroller’s (MC) UART or Serial Interface should be set for
57’600 baudrate, 8 bits data, 1 stop bit, no parity, no flow control.
MC RxD input connects to the FTMINI TXD output
MC TxD output connects to the FTMINI RxD input.

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3.3 Connecting the TS Temperature Probe
The FOTEMP MINI optical interface is via an ST Pigtail. There are two fibers terminated
internally in the ST plug. Use the supplied MR320A ST Bulkhead Adapter to connect TS
sensor probe to the FOTEMP MINI signal conditioner.
Figure 5. How TS Probe is connected to FOTEMP MINI
The proper technique for making ST connection to the FOTEMP MINI :
1. Align key of ST plug with matching key slot of ST adapter.
2. Gently guide the ferrule into the adapter.
3. Twist and engage bayonet pin lock
IMPORTANT NOTE
Never force the ST Plug into the ST Receptacle. Otherwise you might
damage the ST plug and alignment sleeve in the ST adapter.
3.4 System Start-Up
Apply DC power only after all connections have been made.

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4. Serial Communications
4.1 Introduction to UART Operation and Data Frame
The FOTEMP MINI is designed for embedding into the user’s design via a simple 3-wire
UART-based half-duplex serial interface.
UART stands for universal asynchronous receiver / transmitter and defines a
protocol, or set of rules, for exchanging serial data between two devices. UART is very
simple and only uses two wires between transmitter and receiver to transmit and
receive in both directions. Both ends also have a ground connection. Communication in
UART can be simplex (data is sent in one direction only), half-duplex (each side
speaks but only one at a time), or full-duplex (both sides can transmit simultaneously).
Data in UART is transmitted in the form of frames.
As shown in Figure 6, the FOTEMP system’s UART data frame consists of one start bit,
8 bits data, one stop bit, no parity and no flow control – clocked at 57’600 baudrate.
Figure 6. UART Data Frame used by FOTEMP System
One of the big advantages of UART is that it is asynchronous – the transmitter and
receiver do not share a common clock signal. Although this greatly simplifies the
protocol, it does place certain requirements on the transmitter and receiver. Since they
do not share a clock, both ends must transmit at the same, pre-arranged speed in order
to have the same bit timing. The most common UART baud rates in use today are 4800,
9600, 19.2K, 57.6K, and 115.2K. The FOTEMP system transmits at 57,600 baud.

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4.2 FOTEMP ASCII Serial Protocol
The FOTEMP Signal Conditioners use a standard ASCII protocol across its Serial (TTL and
RS232) and USB interfaces. The detailed command and response protocol are described in
Micronor Sensors Application Note AN123. In summary, the FOTEMP MINI recognizes the
following commands:
Read
Command
Description
Sample
Command
Sample Response
Notes
04
Current temperature
of all channels
?04<cr>
or
?04 1<cr>
#04 312<cr><lf>
*00<cr><lf>
Reads temperature
31.2°C
0F
Current channels of
the device
?0F<cr>
#0F4 1<cr><lf>
*00<cr><lf>
FTMINI has only 1
channel
40
Model name
?40<cr>
#40 46 54 4D 49 4E 49<cr><lf>
*00<cr><lf>
Hex equivalent of
FTMINI
41
Serial number
?41<cr>
#41 30 30 36 30 31 39
36<cr><lf>
*00<cr><lf>
Hex equivalent of
S/N 0050196
42
Firmware version
?42<cr>
#41 33 2E 30 33 31<cr><lf>
*00<cr><lf>
Hex equivalent of
Version 3.031
75
Temperature Offset
?75 1<cr>
#75 0000<cr><lf>
*00<cr><lf>
#75 0001E<cr><lf>
*00<cr><lf>
Convert
hexadecimal value
to decimal value in
tenth of Kelvin,
+0.0 K
0x001E converts
to 30 (base10),
+3.0 K
Write
Command
Description
Sample Command
Notes
75
Temperature Offset
In tenth of Kelvin (added to
current temperature offset of
the channel)
NOTE: Offset readings are
stored in 2’s Complement
Binary format. Convert binary
value to decimal value in
tenths of Kelvin, i.e.
+1.0 K =0x000A
-1.0 K =0xFFF6
Assume internal offset value
is +1.0 K
:75 1 000A<cr>
Internal offset becomes
+2.0 K.
?75 1<cr>
returns
#75 0014<cr><lf>
which converts to offet
value +2.0K
Table 1. FOTEMP ASCII Command List

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4.3 Communicating via FOTEMP-Assistant
In this example, a DTECH USB to TTL Serial Adapter (Prolific PL2303TA chipset) was used.
https://www.amazon.com/gp/product/B08BLKBK1K/ref=ppx_yo_dt_b_search_asin_title?ie
=UTF8&psc=1
Serial port connections:
•White (TXD) to FTMINI RxD
•Green (RXD) to FTMINI TxD
•Black (GND) to FTMINI GND
As shown in Figure 7, access Windows Device Manager to note the COMx virtual com port
assignment under Ports (COM & LPT). Click on the COMx port assigned to your device
(COM4 in this example) and set the FOTEMP-compatible Port Settings as follows:
•Bits Per Second=57600
•Data bits=8
•Parity=None
•Stop Bits=1
•Flow Control=None
Figure 7. Setting Serial Port Settings via Device Manager

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Run FOTEMP-Assistant V2.3.0.22 or later (consult separate FOTEMP-Assistant V2 manual).
Select [Devices/Search/Search ASCII Devices] and FOTEMP ASSISTANT will start reading the
FOTEMP MINI.
For One-Point Calibration of replacement TS sensor, select [Devices/Settings] and Device
COMx. Adjust Offset value field until FOTEMP MINI displays same reading as your
designated TC Reference.
4.4 Direct Serial Communications via PuTTY Terminal Emulator
In this example, a DTECH USB to TTL Serial Adapter (Prolific PL2303TA chipset) was used.
https://www.amazon.com/gp/product/B08BLKBK1K/ref=ppx_yo_dt_b_search_asin_title?ie
=UTF8&psc=1
PuTTY terminal emulator (shareware) can be download here:
https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
Serial port connections:
•White (TXD) to FTMINI RxD
•Green (RXD) to FTMINI TxD
•Black (GND) to FTMINI GND
As shown in Figure 7, access Windows Device Manager to note the COMx virtual com port
assignment under Ports (COM & LPT). Click on the COMx port assigned to your device
(COM4 in this example) and set the FOTEMP-compatible Port Settings as follows:
•57,600 bits per second (baudrate)
•8 Data bits
•No Parity
•1 Stop bit
•No Flow control
Run PuTTY and open a Session with the following parameters:
•Session menu – select Serial mode, enter COMx port and Speed=57600.
•Terminal menu – set Local Echo=Force ON, Local Line Editing=Force ON
•Connection/Serial Menu – set Data Bits=8, Stop Bits=1, Parity=none, Flow
Control=none
•Go back to Session menu and name and save Session for future sessions
•Click on [Open] to start session
Reference the ASCII commands summarized in Table 1 and discussed in more detail in
Application Note AN123.As an example, enter “?04<cr> to read the current temperature.
Example:
See Figure 8 for example of ASCII command dialog with FOTEMP MINI using PuTTY terminal
emulator. Converted responses are shown to the left.

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Figure 8. Example of FOTEMP MINI Serial Communications Dialog using PuTTY
4.5 Sample Arduino Program
Figure 9. Sample Arduino Program

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5. FOTEMP MINI Specifications
Temperature Measurement
No. of Channels
1
Measuring Range
-200°C to +300°C, depending on Calibration option and TS
sensor used
Resolution
0.1°K
Accuracy
± 0.2°K (1 sigma) when used with TS sensor used during
Factory Calibration
± 0.5°K (1 sigma) when used with TS sensor used for One-
Point Calibration
Calibration Options
(as ordered)
A Calibration (standard) = -40°C to +200°C
B Calibration (high temperature) = -40°C to +300°C
C Calibration (extended temperature) = 200°C to +300°C
Measuring Rate
250ms
Electrical Interfaces
Serial Interface
3.3V TTL UART – Rx, Tx, GND
57’600 Baud, 1 Start bit, 8 Data bits, 1 stop bit, no parity
Serial Protocol
Stancard Optocon ASCII protocol as described in Application
Note AN123
Power Supply
+7 to +12VDC, <700mA
Optical Interface
Eye Safe
Interface
ST-PC Simplex, Compatible with all TS series GaAs FO
temperature probes
200/220/245 Polyimide-Coated Step Index Fiber, VIS-IR,
Low OH
Source Type
Broadband white light
Maximum Optical Link
Length
Up to 2000m
NOTE: Actual distance depends on total link loss – fiber,
connectors and splices
Environmental Performance
Temperature/Humidity
Operating
Storage
Humidity
-20° to +60°C
-20° to +70°C
25% to 95% RH (non-condensing)
Ingress Protection
IP00 (None)
Physical Attributes
Physical Attributes
Dimensions
48.4mm L x 64.9mm W x 32.6mm H
Unit Weight
140g (22 oz.)
Specifications subject to change without notice

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6. FOTEMP MINI Theory of Operation
As shown in Figure 10, the FOTEMP MINI operates on the same theory of operation as the
FOTEMP signal conditioners.
Figure 10. FOTEMP MINI Theory of Operation
As shown in Figure 11, GaAs-based fiber optic temperature probes and FOTEMP signal
conditioners are deployed wherever conventional convention thermocouples cannot be
used.
Figure 11. Advantages of GaAs Fiber Optic Thermometry versus Thermocouples

MICRONOR SENSORS FOTEMP MINI OEM Signal Conditioner
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7. FOTEMP MINI Reference Drawing