RMT Ltd. Thermoelectric Module Controller DX5100-Frame Quick Start User Guide RMT Ltd. Moscow, 2015 Version 1.04 DX5100-FRAME. Quick Start RMT Ltd. Table of Contents Features and benefits .................................................................................................................................. 3 Specifications .............................................................................................................................................. 3 General .................................................................................................................................................... 3 Performance............................................................................................................................................. 3 Options .................................................................................................................................................... 4 Dimensions .............................................................................................................................................. 5 Thermal mounting considerations................................................................................................................. 6 How to Get Connected ................................................................................................................................. 6 Connection terminals in case of one channel design ................................................................................. 6 Connection terminals in case of two channels design................................................................................ 6 Connector descriptions ............................................................................................................................. 6 TEC Connection ....................................................................................................................................... 7 Thermistor Connection ............................................................................................................................. 7 Power Connection .................................................................................................................................... 8 DX5100 Vision ............................................................................................................................................. 8 Thermistor Settings ...................................................................................................................................... 9 Procedure Description .............................................................................................................................. 9 Thermistor Current Settings ...................................................................................................................... 9 Choice of Thermistor Type ......................................................................................................................11 Temperature as Function of Resistance: ..................................................................................................11 Calibration of Temperature Measurement Channel ..................................................................................12 Setting Alarm Limits ....................................................................................................................................13 Setting Limits of TEC Voltage ..................................................................................................................13 Setting Temperature Limit Values ............................................................................................................14 PID Tuning..................................................................................................................................................16 PID Tuning Tips ......................................................................................................................................16 PID Tuning..................................................................................................................................................18 PID Tuning Tips ......................................................................................................................................18 Operation Modes ........................................................................................................................................20 Autostart .................................................................................................................................................20 Mode "Program" ......................................................................................................................................21 T-Regulation (Relay) ...............................................................................................................................21 PID regulation (Constant Temperature) ...................................................................................................21 Constant Voltage .....................................................................................................................................21 Monitoring...................................................................................................................................................21 Working with LCD and buttons ....................................................................................................................23 TEC Control: DC versus PWM ....................................................................................................................25 Page 2 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Features and benefits - Bi-directional temperature regulation (heating and cooling) of a TEC with high accuracy - Work with RTD sensor and thermistors of both NTC and PTC types (known T=f(R) Resistance range 70 Ohm …996 kOhm) - One or two TECs controlled by one Controlling Board - Power channels of two versions: high-power 4Aх8V and low-power 3Aх5V - TEC operation current and voltage range as ±4A and ±8V per channel. - PID temperature regulation mode - Constant voltage operation mode - T-Regulation (relay) mode - Temperature programming in time - DC regulation of TEC in all operation modes - Diagnostics of TEC performance by the Z-metering approach - PID auto-tuning function - Independent work without remote computer, based on preset and programmed start - Communication interfaces RS232 and RS485 - Networking of up to 32 channels by RS485 bus - Software for RS232 and RS485 protocols - Protocol WAKE for user software programming Specifications General Name Units Value Comments Operation Modes PID Constant voltage Temperature Program Т-regulation (relay) Yes Yes Yes Yes Yes PC control/programming Stand-alone pre-programmed operation (boot start) Yes USB RS485 WAKE 32 (128) Communication interfaces Communication protocol Maximum number of channels in network Programmable thresholds Temperatures Max voltage Operational temperatures range Storage temperatures range Humidity Power supply TEC bi-directional (heating and cooling) °C °C % V 2 1 0…+45 -20…+60 5…95% 12.0+/-10% BIN & SYM Combined by RS485 Every Channel Performance Maximum current Maximum voltage Maximum power Maximum current Ver. 1.04. 2015 Name Units Value Absolute Maximum Parameters (Options: Frame 1…4) A 4 V 8 W 32 Absolute Maximum Parameters (Options: Frame 5, 6) A 3 Comments Per channel Per channel Page 3 / 25 DX5100-FRAME. Quick Start RMT Ltd. Name Units V W Value Maximum voltage 5 Maximum power 15 Regulation channels number 2 Parameters of TEC Voltage Regulation Voltage Range V -8…+8 Voltage Range V -5…+5 Accuracy of voltage regulation mV 1 Resolution of voltage setting mV 0.13 Measurement resolution 6 V Output ripple, not more 10 V Efficiency of converters % 85 Temperature Regulation 4-wire sensing Yes Resolution °C 0.001 Stability °C 0.005 Accuracy °C 0.5 Types of Thermosensors Platinum thermistor Pt Other types of thermistors NTC, PTC Resistance range Ohm 70…996K Mode «Program» Programs number, max 16 Program steps number, max 50 Steps number in a process 800 Program step duration, max s 65 535 Time interval accuracy s 1 Operational modes switch along with Yes temperature programming in time Programs cascading Yes Comments Digital Board Options: Frame 1…4 Options: Frame 5, 6 Typical values. Depend on thermistors type Known T=f(R) 0..15 0..49 Programs in series All parameters are specified at ambient temperature 23±5°C and humidity 45±15% Options The controllers DX5100 Frame are available in six equipment options Device Option Frame 1 Frame 2 Frame 3 Frame 4 Frame 5 Frame 6 Channel parameters 8V x 4A 8V x 4A 8V x 4A 8V x 4A 5V x 3A 5V x 3A Number of channels 1 1 2 2 2 2 Display module + + + Frame type Low profile Normal profile Normal profile Normal profile Low profile Normal profile Overall dimensions, mm 126x114x21 126x114x28 126x114x28 126x114x28 126x114x21 126x114x28 Weight, g Important! The DX5100 Table Top controller is based on DC current regulation by TEC in all operational modes for maximum cooling efficiency (See chapter “TEC Control: DC versus PWM”). Page 4 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Dimensions Normal profile housing 2 1 6 Frame 2 Frame 3 Frame 4 Frame 6 7 4 5 3 Recommended Airflow Direction Low profile housing 2 1 Frame 1 Frame 5 4 5 3 1 2 3 4 5 6 7 Ver. 1.04. 2015 Housing base Cover Connecting terminals Power switch Connector miniUSB Indicator (LCD Display) (only Frame 2, 4, 6) Control buttons (only Frame 2, 4, 6) Page 5 / 25 DX5100-FRAME. Quick Start RMT Ltd. Thermal mounting considerations The DX5100 FRAME controllers may generate a significant amount of heat. Heat generated must be adequately removed in order to prevent the controller from overheating. An external heat sink is necessary, and active air circulation may be required depending on ambient temperature and power supplied to TECs. Important! Ensure adequate heat dissipation from DX5100 in order to prevent its overheating . How to Get Connected There are connection terminals on one side of the controller. There are two terminal versions, depending on the number of channels. Connection terminals in case of one channel design RS485 A TEC1 B GND 1 2 3 Rt1 F 4 5 6 7 8 9 S OUT1 S INPUT 1 F 10 11 12 13 14 15 12VDC E 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Connection terminals in case of two channels design RS485 A B GND 1 2 3 TEC2 Rt2 F S TEC1 S F 4 5 6 7 8 9 Rt1 F S OUT2 S F 10 11 12 13 14 15 OUT1 2 INPUT E 1 12VDC E 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Connector descriptions Contact # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Page 6 / 25 Circuit Signal A of interface RS485 Signal B of interface RS485 Signal GND of interface RS485 TEC+ TECF+(force) connections to thermistor. S+(Kelvin sense) connections to thermistor. S- (Kelvin sense) connections to thermistor. F- (force) connections to thermistor. TEC1+ TEC1F+(force) connections to thermistor. S+(Kelvin sense) connections to thermistor. S- (Kelvin sense) connections to thermistor. F- (force) connections to thermistor. Normally closed contact of the relay Chanel Common relay Chanel Normally open contact of the relay Chanel Normally closed contact of the relay Chanel Common relay Chanel Normally open contact of the relay Chanel Control of channel (digital input) Common of digital input Enables to control (digital input) Control of channel (digital input) Common of digital input Notes RS485 Channel 2 Channel 1 Channel 2 Channel 1 Channel 2 Channel 1 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Contact # 27 28 29 Circuit Enables to control (digital input) Power + Power - Notes Power Supply TEC Connection Important! Ensure proper heat dissipation from a hot side of your TEC by using proper heatsink and good thermal contact between TEC hot side and a heatsink. Important! Any TEC must be connected according to its polarity to operate in cooling mode . Thermistor Connection Important! The position of temperature sensor (thermistor) must be carefully selected according to the design of an object (heat load) on a cold side of TEC. The design must ensure minimum possible temperature gradient between the thermistor and TEC cold side. Perfect thermal contact between the thermistor and an object (heat load) is required.. The thermistor may be connected by a 4-wire or 2-wire connection as shown on the figure below. We recommend always connect the thermistor by two twisted pairs for 4-wire circuit. 2-wire connection may be used for thermistor resistance exceeding 1000 Ohm. For this connection, correspondent connecting terminals contacts should be bridged (contacts 12-13 and 14-15 in channel 1, contacts 6-7 and 8-9 in channel 2). TEC Rt F S TEC S F 4 5 6 7 8 9 10 11 12 13 14 15 Rt F Channel 2 Channel 1 4-wire connection of thermistor S S F 4 5 6 7 8 9 10 11 12 13 14 15 Channel 2 Channel 1 2-wire connection of thermistor Connection of TEC and thermistor to the controller Ver. 1.04. 2015 Page 7 / 25 DX5100-FRAME. Quick Start RMT Ltd. Power Connection Connect a power supply observing correct polarity. A power supply source should provide voltage 12±10% V. Important! Power supply must be chosen basing on total power consumption of the controller. Power supply must provide at least 80 W output if 2 x 32 W regulation channels are used at full power. Less powerful supplies may be used otherwise. In any case, power available from power supply must exceed total power output of both regulation channels by at least 20%. DX5100 Vision You will need a PC to get DX5100 controller up and running when you switch it for the first time. Note you may not need PC after you stored your programs/settings in DX5100 controller. Connect the controller to a computer via the cable miniUSB. By default, the controller has a rate setting of 19200 kbps. DX 5100 needs one command and one noncommand interface. When the program runs, it scans serial ports of the system and determines the command interface of the connected controller DX5100. Another COM-port is highlighted by colour next to it. This is a noncommand interface. Select both COM-ports and click on «Open». Page 8 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Thermistor Settings Important! All controllers are set to “Idle” mode before shipment. The controller must be in “Idle” mode if you set or re-set any parameter. This excludes permanent failures and fatal damages during the procedure, which are possible otherwise. Check operation mode carefully before starting any setting or re-setting procedure. Attention! It is strongly recommended to back up the parameters of the controller before adjusting the thermistor. See "Backup/restore of parameters". DX5100 Vision. Technical Manual. Procedure Description The thermistor setting means finding and storing parameters of the ADC channels for each thermistor in the non-volatile memory. Thermistor Current Settings At first, you can check current settings of the thermistor and estimate the accuracy of measurements. Click on «Show current Thermistor settings» The program will read the data of thermistor currently set in controller, and will try to identify the thermistor. If the coefficients match to the predefined (internal library) values, the following information will be displayed: Ver. 1.04. 2015 Page 9 / 25 DX5100-FRAME. Quick Start RMT Ltd. If the coefficients do not match to data in internal library (i.e. the sensor is unknown), the program will build the dependence of temperature versus resistance to obtain the coefficients and determine the sensor nominal). Page 10 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Choice of Thermistor Type To simplify the setup procedure, the program offers a choice of predefined characteristics of thermistors from the library. The list includes 4 platinum thermistors and 47 NTC thermistors with different alpha and beta coefficients. If the sensor you use is on the list, just select it and go to the next section, "Calibration of temperature measurement channel". Otherwise, you must define and set the thermistor data by using "User defined" option. The program will ask you to choose a type of R(T) function (see below), and operating temperature range. It is important that normal ambient conditions (usually 25+/-5 oC) are within the range you selected. Temperature as Function of Resistance: The controller allows using 2 types of functions for calculating temperature versus resistance: Polynomial 5th order function: 𝑻 = 𝑨𝟎 + 𝑨𝟏 𝑹 + 𝑨𝟐 𝑹𝟐 + 𝑨𝟑 𝑹𝟑 + 𝑨𝟒 𝑹𝟒 + 𝑨𝟓 𝑹𝟓 Steinhart-Hart equation: 𝟏 𝑻 = 𝑨 + 𝑩 𝒍𝒏(𝑹) + 𝑪 𝒍𝒏(𝑹)𝟑 When Steinhart-Hart equation method is selected, you must enter 3 different values of temperature and correspondent resistance. This information is usually provided by a thermistor manufacturer. Two values should be at the extremes of working range, while the the third one in a middle between extremes. The difference between values must be at least 10 K. Ver. 1.04. 2015 Page 11 / 25 DX5100-FRAME. Quick Start RMT Ltd. The Steinhart-Hart equation describes NTC thermistors very well. When choosing a polynomial function, correspondent coefficients must be entered, also available from thermistor manufacturer. Results of calculations may be checked by clicking "Calc". Calibration of Temperature Measurement Channel Click the button «Calibrate». The program will ask for the confirmation: Double-check parameters and click OK. Then select the calibration mode. Automatic mode must be chosen. The controller will be preset according to parameters of your thermistor (either chosen from the list of standard thermistors, or “User defined” as described above). Page 12 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start If necessary, the current settings of the thermistor can be checked and the accuracy of measurements can be assessed. This procedure is described in details in the section «Viewing Current Settings of Thermistor. Checking Measurements.» DX5100 Vision. User Guide. Briefly, you can check the agreement of the calculated and experimental values using the fields for resistance or temperature inputs in «Check function of approximation» (upper boxes on the screenshot below). The block «Measurement of the resistance of the thermistor» allows more detailed verification of correct functioning of the temperature measurement channel by clicking on “Measurement”. Setting Alarm Limits Setting Limits of TEC Voltage Select correspondent option in DX5100 VISON menu : Ver. 1.04. 2015 Page 13 / 25 DX5100-FRAME. Quick Start RMT Ltd. Important! To prevent a thermoelectric cooler (TEC) failure, it is necessary to set correct limit values of TEC voltage. Refer to the TEC specifications . Setting Temperature Limit Values Select correspondent option in DX5100 VISON menu. The tab "Limiting temperatures" allows to specify the maximum and minimum “limit” temperatures. If the temperature is out of these limits for the time specified, a corresponding alarm is on and the channel is switched off automatically. The meaning of the parameters to be set is illustrated by the following picture. Page 14 / 25 Ver. 1.04 2015 RMT Ltd. Ver. 1.04. 2015 DX5100-FRAME. Quick Start Page 15 / 25 DX5100-FRAME. Quick Start RMT Ltd. PID Tuning Select “PID tuning” in “Operation” menu of DX5100 VISION. There is a tab to fine-tune the PID of the controller as shown below. Here you can set the PID controller coefficients and check transient process of reaching the setpoint at different values of the coefficients. Finding of optimum parameters of regulation of the given object is quite a delicate and relatively long procedure. It is a consecutive experimental tuning of parameters. Details may be found in DX5100 Technical Manual. Attention! Factory PID settings are just the most common values. Use of the controller without initial PID check and its tuning having your particular TEC and object (heat load) connected may result in non-proper temperature control and system failure. Controller DX5100 has “auto-PID” option allowing to simplify the choice of optimum P-I-D finding considerably. We recommend always use auto-PID for checking/setting of PID parameters for the first time. The function realizes the Ziegler-Nichols algorithm. To run auto-PID, select PID setpoint temperature in menu. Setpoint temperature should be the same as nominal stabilization temperature of your object. Then click on “AUTO-PID” in the PID Setting menu. When the process is finished, all coefficients will be displayed in correspondent bars and transient process will be plotted. If you are not satisfied by transient process you can tune PID coefficients further by yourself. The chapter “PID tuning tips” below describes how different constants affect transients and overall quality of temperature stabilization. Note the “tips” describe the procedure since the very beginning. We recommend to play around values obtained by using “auto-PID” procedure, using “start” and “stop” to check the result of every change. Attention! Maximum TEC voltage must be set BEFORE starting auto-PID Attention! Note the manufacturer does not guarantee the parameters obtained using built-in auto-PID function are the most optimum. It is recommended to check the obtained parameters and, if necessary, to carry out more accurate tuning of the PID parameters depending on the required quality of the thermal regulation. PID Tuning Tips The tuning quality can be estimated by different criteria: by the rate of achieving the setpoint, by the minimal overshot, by accuracy of setpoint maintenance. The tuning quality can also be estimation by the transient process of achieving the setpoint. Recommendations for PID tuning by the form of the starting curve are given below. 1. Set values of integrated and differential components equal to zero: Ki=0; Kd=0 Modify the value of the proportional component factor Kp so that the form of the transient process corresponds to that of curve 2 or 3 (see the figure below). Page 16 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Kp1>Kp2>Kp3>Kp4>Kp5 Ttarget T0 2. Modify the value of the differential component factor Kd so that the form of the transient process corresponds to that of curve 2. Ttarget T0 3. The integrated component Ki is intended to remove a residual mismatch between the temperature value achieved in the system and the setpoint. Modify the value of the proportional component factor so that the form of the transient process corresponds to that of curve 3 (one relaxation spike with minimum possible overshoot). Ttarget T0 The figure below shows an example of results of manual changing of PID coefficients on controller performance. Ver. 1.04. 2015 Page 17 / 25 DX5100-FRAME. Quick Start RMT Ltd. PID Tuning Select “PID tuning” in “Operation” menu of DX5100 VISION. There is a tab to fine-tune the PID of the controller as shown below. Here you can set the PID controller coefficients and check transient process of reaching the setpoint at different values of the coefficients. Finding of optimum parameters of regulation of the given object is quite a delicate and relatively long procedure. It is a consecutive experimental tuning of parameters. Details may be found in DX5100 Technical Manual. Attention! Factory PID settings are just the most common values. Use of the controller without initial PID check and its tuning having your particular TEC and object (heat load) connected may result in non-proper temperature control and system failure. Controller DX5100 has “auto-PID” option allowing to simplify the choice of optimum P-I-D finding considerably. We recommend always use auto-PID for checking/setting of PID parameters for the first time. The function realizes the Ziegler-Nichols algorithm. To run auto-PID, select PID setpoint temperature in menu. Setpoint temperature should be the same as nominal stabilization temperature of your object. Then click on “AUTO-PID” in the PID Setting menu. When the process is finished, all coefficients will be displayed in correspondent bars and transient process will be plotted. If you are not satisfied by transient process you can tune PID coefficients further by yourself. The chapter “PID tuning tips” below describes how different constants affect transients and overall quality of temperature stabilization. Note the “tips” describe the procedure since the very beginning. We recommend to play around values obtained by using “auto-PID” procedure, using “start” and “stop” to check the result of every change. Attention! Maximum TEC voltage must be set BEFORE starting auto-PID Attention! Note the manufacturer does not guarantee the parameters obtained using built-in auto-PID function are the most optimum. It is recommended to check the obtained parameters and, if necessary, to carry out more accurate tuning of the PID parameters depending on the required quality of the thermal regulation. PID Tuning Tips The tuning quality can be estimated by different criteria: by the rate of achieving the setpoint, by the minimal overshot, by accuracy of setpoint maintenance. The tuning quality can also be estimation by the transient process of achieving the setpoint. Recommendations for PID tuning by the form of the starting curve are given below. 3. Set values of integrated and differential components equal to zero: Ki=0; Kd=0 Modify the value of the proportional component factor Kp so that the form of the transient process corresponds to that of curve 2 or 3 (see the figure below). Page 18 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Kp1>Kp2>Kp3>Kp4>Kp5 Ttarget T0 4. Modify the value of the differential component factor Kd so that the form of the transient process corresponds to that of curve 2. Ttarget T0 3. The integrated component Ki is intended to remove a residual mismatch between the temperature value achieved in the system and the setpoint. Modify the value of the proportional component factor so that the form of the transient process corresponds to that of curve 3 (one relaxation spike with minimum possible overshoot). Ttarget T0 The figure below shows an example of results of manual changing of PID coefficients on controller performance. Ver. 1.04. 2015 Page 19 / 25 DX5100-FRAME. Quick Start RMT Ltd. Operation Modes There are several modes of regulation available by DX5100: Idle (Regulation is off) Mode "Program" T-regulation (relay) PID regulation Constant voltage maintenance To run the device, you should select operation mode first. You should also decide whether you’ll continue to control DX5100 by PC or not. If you will continue controlling of DX5100 by a PC, you should simply select operating mode required and start/stop regulation using VISION ( see “Monitoring” section below). If you do not plan to use PC further, you should select regulation mode and switch DX5100 to “Autostart” mode as described below. Temperature regulation will start immediately upon switching on of a DC power supply. Autostart DX5100 may be used stand-alone (without a computer) by using “Autostart” option. Factory setting is “idle”, but controller may be switched to “Autostart” operation when operation mode is changed from “Idle”. In this case, object temperature will be controlled automatically upon applying of 12 V DC power to DX5100. The mode required must be selected by using “Boot Mode” tab in DX5100 VISION. Page 20 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Mode "Program" The Controller may operate programs stored in the non-volatile memory. There is a tab “Program manager” in VISION for modifying programs of temperature change in time. Please check DX5100 Technical Manual for more details. Note no programs are provided by RMT unless agreed before purchase. T-Regulation (Relay) Immediately after starting this mode, the TEC maximum allowable voltage is supplied to the TEC for the most rapid achievement of the setpoint. Heating or cooling mode is chosen depending on the sign of the mismatch between current temperature and the setpoint. After reaching the setpoint the TEC is exposed to the stepped voltage equal to the specified value UTreg (see DX5100 Technical Manual for details). Depending on the mismatch (the difference between the setpoint and actual temperature) and on the sign of the voltage, either UTreg or 0 volts is supplied. The described process is explained by the figure below. T[K] 296 294 292 290 288 286 284 282 Tneed=280K U[V] UTECmax=8V UTreg=2V 0 PID regulation (Constant Temperature) The given mode provides maintenance of constant temperature of an object (TEC). Maintenance of The mode provides maintenance of constant temperature of an object (TEC). Maintenance of temperature is carried out by TEC voltage calculated according to PID regulation. This method provides the most precise temperature stabilization by TEC. Both TEC voltage and polarity are automatically controlled in this mode. The PID coefficients are set by the User as described above. Constant Voltage In this mode the TEC constant voltage is maintained. A User should set a value of constant voltage including the sign. Note the sign «-» stands for the heating polarity. Monitoring The mode allows monitoring changes of up to two parameters in time simultaneously, as well as a current operating mode. In addition, you can start and stop any regulation mode there. For details, please check the screenshot below. Ver. 1.04. 2015 Page 21 / 25 DX5100-FRAME. Quick Start Choice of parameter of plot 1 RMT Ltd. Regulation start and stop buttons Monitoring start and stop buttons Current value of parameter of plot 1 Current value parameter of plot 2 of Choice of parameter of plot 2 Modes Some versions of DX5100 FRAME have a display indicating the main parameters, and two control buttons. You can select parameters you wish to monitor (set and actual temperature in both channels, TEC voltage and current, etc) by using these buttons, as it is shown on the figure below. It is important that control buttons may be used for switching temperature regulation on and off independently on whether DX5100 is controlled by a PC or not. Please refer DX5100 Technical Manual for more details. Page 22 / 25 Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start Working with LCD and buttons On the LCD of the board there are the parameters corresponding to a certain mode. There are 8 screens of indication: E1 Indication of temperatures and setting values E5 Device identification E2 Indication of channel TEC1 E6 Control (launch programm) E3 Indication of channel TEC2 E7 Set TEC1 setpoint (launch PID) E4 Status E8 Set TEC2 setpoint (launch PID) № Screen E1 Description TEC2 temperature* TEC1 temperature* TEC1 setting TEC1 temperature* E2 TEC1 setpoint TEC2 temperature* E3 TEC2 setpoint TEC2 setting channel number TEC1 regulation mode** channel number TEC2 regulation mode** STATUS Ch1- TEC1 regulation mode** Name and version of the firmware E4 E5 TEC1 voltage TEC1 current TEC2 voltage TEC2 current XXXX*** Ch2- TEC2 regulation mode** Network address and identifier Device serial number & Date of release START Pr-NN if mode is OFF E6 STOP if mode is not OFF If there is not pressed button for 5 seconds, it will return to the E2 or E3 screens. TEC1 temperature* channel number TEC1 voltage E7 TEC2 temperature* ** setting TEC1 setpoint TEC1 setpoint E8 * (NN= 00…15 program number) TEC1 if from E2 TEC2 if from E3 TEC2 setpoint channel number setting TEC2 setpoint TEC1 current TEC2 voltage TEC2 current Indication "------" (instead of the temperature) occurs for values of thermistor resistance, exceeding the maximum for the range, which is configured ADC. Mnemonic designations are applied for a mode of regulation: OFF Regulation is disabled PRG According to program REL T-regulation (relay) PID PID temperature control VOL Constant voltage OK Temperature is within the setting. The criterion of signal of settling is right (see command 0x49) ERR Ver. 1.04. 2015 Temperature is beyond the limitations (see commands 0x3C 0x3D) Page 23 / 25 DX5100-FRAME. Quick Start *** RMT Ltd. Status displays in hexadecimal. Values status bit: 0x0001 error EEPROM 0x0002 unknown command 0x0004 no ready data for telemetry (response) 0x0008 TEC voltage at Z-metering does not drop for too long 0x0010 error in parameters or command format 0x0020 reception RS-232 buffer overfilling 0x0040 reception RS-485 buffer overfilling 0x0080 voltage supply error 0x0100 TEC1 temperature is beyond the limitations 0x0200 TEC2 temperature is beyond the limitations 0x0400 TEC1 temperature is within the setting 0x0800 TEC2 temperature is within the setting 0x1000 Command performance is interrupted Since the Firmware version 341 it is possible to set the first (after boot) screen with the command 0x54. Also, 0 using the command 0x54 it is possible to choose unit temperature display - in Kelvin (K) or in degrees Celsius ( ). Switching between the screens graph illustrates: To setpoint N 2 mode=PID L Lt R Rt To=To-1 To=To+1 Lt R Rt L L R 1 mode=OFF L Lt R Rt 0 R 2 N L mode=PRG R L L R Pr=Pr-1 Pr=Pr+1 mode=OFF Lt Rt To setpoint N 2 mode=PID L Lt R Rt To=To-1 To=To+1 The graph used the notation: L – left button, single click; R- right button, single click; 1 mode=OFF L Lt R Rt 0 Rt – right button,hold; Lt – left button,hold; 2 – two buttons click; N – no clicks of any button in 5 seconds. Page 24 / 25 2 mode=PRG N Pr=Pr-1 Pr=Pr+1 mode=OFF Ver. 1.04 2015 RMT Ltd. DX5100-FRAME. Quick Start TEC Control: DC versus PWM Thermoelectric Temperature Controllers usually use PID or PI (proportional–integral–derivative or proportional–integral) regulation for temperature control and stabilization. Such a controller “calculates” an “error signal” as the difference between measured “actual” temperature (current thermistor value) and a desired setpoint (preset value). This “error signal” is then used to generate correspondent change of TEC voltage to compensate the difference between set and current thermistor values. A thermoelectric cooler (TEC) is a DC device. So DC signals are usually applied to it. However pulse-width modulation (PWM) is widely used to supply TECs nowadays, as this method is relatively cheaper with respect to DC modulation. In case of PWM, TEC is powered up by a train of pulses with a fixed period T and amplitude Im, but with duty cycle changing in time In other words, a TEC is supplied by some “average” effective current I0 which value changes in time as a function of duty cycle, I0=f(/T). Im I0 t T PWM electric current vs time. I0 – average current, duty cycle is /T PWM works well for instance for resistive heaters, LEDs and others. However, an alternating current of any nature can be detrimental to TEC efficiency (temperature difference). Let us consider TEC supply (electric current or voltage) in PWM as a superposition of the averaged and fast variable values. The average value results in the thermoelectric cooling, however, the variable one produces Joule heating only. This may affect TEC efficiency considerably. As an example, the figure below illustrates performance of a single-stage 30-pair thermoelectric cooler 1MC06-030-05 (manufacturer – RMT Ltd.) in case of PWM and DC supply. TEC 1MC06-030-05 Thot=300 K, vacuum a) Temperature dirrefernce vs DC or PWM average currents b) Power consumption to reach temperature difference by DC or PWM average currents Comparison of DC and PWM supply of TEC. TEC type 1MC06-030-05 (RMT Ltd.) PWM with different amplitude currents Im=2, 3, 4 A and duty cycles changed from 0…1 was used. TEC efficiency degradation in case of PWM is clearly seen. The use of PWM always results in lowering of TEC performance in cooling mode, and in higher power consumption in comparing to DC supply of TEC. So we consider DC supply as more efficient than PWM when used for cooling by TECs. This explains why DC control is used in our DX5100 controllers. Important! The DX5100-Frame device series is based on DC current for all operational modes for maximum possible cooling efficiency. Ver. 1.04. 2015 Page 25 / 25