Proportional and Integral (PI), Temperature Controller using 2 Loads (Load1 for
Heating and Load2 for Cooling), with
12-Bit Digital Temperature Sensor, Two RS232 Ports, Integrated
Networkable 9600-Baud RS232
Input/Output Control Port:
For Set-Temperature and control
parameter Input; and for
Measured Temperature and Control parameter Output . All control
parameters are stored in nonvolatile memory. Up to 61 Networkable Boards can be interconnected
to form a 3-wire Local Area Network, LAN.
PI Temperature Control:
Proportional and Integral (PI) Temperature Controller
in the -500C to +1200C Range with 0.0650C steps
using 2 Loads. Heat on Load 1 and Cool on Load 2.
The Set-Temperature is selected with a network command.
One Digital Temperature Sensor:
A Digital Temperature Sensor with 0.06250C
and 1/20C Accuracy
-100C to +800C Range, and approx.
-550C to +1250C Range.
Temperature Sampling Rate:
The temperature is sampled at approximately 1Hz rate and the
control-loop/display is updated with this same rate.
An Optional LCD Port:
For Set and Measured Temperature Display.
open switch (or an Open Collector npn Transistor) can be connected
to jumper J1 (as shown below), J1 Open=Normal operation, J1
Short=Load (TE Cell) is open.
PWM Load Control: Two 60A MOSFETs are used to PI control the power to two
Heating and Load2 for Cooling,
two Valves , TE cells, etc) using 750 Hz Pulse-Width Modulation.
98.5% typical, at 30V and 20A
Voltage Requirement: A single DC Source Voltage (unregulated )
with any voltage value from 9V to 30V DC (for Vp) at 20A max.
Max Operating Temperature:
With the Integrated Finned Heat Sink, as shown.
Max Load Power: 600W at 30V, 20A.
Overall Dimensions: L=2.4", W=2.3",H=2.1" (61 x
58 x 52mm).
Components Type: 100% Solid State, NO
On Board: Filter Capacitors, Voltage Transient Suppression (VTS)
diodes, One Load-Current Indicator LED (Red=Hot/Cold).
is a 30V, 2x16A, Networkable, Proportional and Integral (PI) Temperature
Controller using 2 Loads (Heat and Cool at the same time). The fundamental
components of this controller are: a 12-Bit digital temperature sensor; two
high-power transistors (FETs); and a networkable microprocessor that stores the
selected control parameters in a nonvolatile memory and controls the power
flow to two loads (Valves, Thermo-Electric (TE) cells, etc) using 750Hz
Pulse-Width Modulation (PWM). The temperature is measured with a 12-bit
digital sensor and the process is PI controlled with 0.06250C steps
in the -500C to +1200C range. By PI control, we
mean that the amount of correction used in the control-loop is proportional to
the difference and the Integral of the difference between the set and measured
temperature values. A single DC power supply (in the 9V to 30V and 0A to 20A
range) is required to operate this controller. Two proportional-band parameters
are used “c”= 001,...199 for Cold band, and “h”= 001,...199 for
Heat band. One step change in the band parameter represents a 1 degree C change.
Two control bands are used because the TE cells are more efficient in heating
mode than in the cooling mode. These proportional control bands are centered at
the set-temperature value; and a smaller band value represent more aggressive
proportional control. Full heating or cooling TE-cell power (100% PWM) is used
when the measured temperature is outside of this selected band; and reduced
TE-cell power (100% to 0% PWM as specified by the PI control) is used
inside this band. The integral gain “i”= 001,...199 controls the
contribution of the integrator to the total PI control sum. Larger
integral gain values represent higher integral contribution (“i”=199
represents 100% contribution). The integrator is reset to zero each time a new
set temperature is selected and its growth is limited to prevent excessive
integral contribution ( “integral windup”). A wide range of thermal loads can be
efficiently controlled with proper control parameter selection.
The temperature overshoots and oscillations (“hunting”)
are limited to approximately + or - 0. 50C. Control
parameter selection and PI tuning are defined in the network
section of the Manual. The temperature is sampled at approximately 1Hz rate
and the control-loop/display is updated with the same rate.
A Typical Application of the
12-bit, closed-loop, PI temperature control application, the
Set-Temperature is adjusted by command strings derived from a Personal Computer
(PC) using the Microsoft “Hyper Terminal” program (or any-other ASCII controller
operating at 9600 Baud, 1 start-bit, 8 data-bits, 1 stop-bit, No parity-bit). In
this application, one Peltier type Thermo-Electric (TE) cell is used (for
heating-only in the heat mode and for cooling-only in the cooling mode, as
selected by the ‘m’ command). The TE cells can be purchased from: www.customthermoelectric.com/.
The temperature of the enclosed and insolated Hot/Cold Environment is measured
with the Dallas Semi. DS18B20 (in TO-92 casing) Digital Thermometer,
Si24DTsens-Spec1-DS18B20.This sensor can be purchased from Signal
Consulting, LLC as
(DS18B20 with 12” leads and 3-pin connector). The
optional LCD module can be ordered from Signal using the part number of
(2x16 serial LCD with
back-light, 12” cable and with 4-pin connectors).
The connecting wires to the Load and the Power Supply must be heavy gauge copper
wire (#12 AWG or heavier) to handle the rated current level. In addition, these
heavy gauge wires act as a heat sink, preventing overheating.
Command Format and Local Area Network (LAN)
Each board has a unique,
8-bit, ASCII, none-volatile, Node-Address ranging from 1….9, A..Z, a,…z;
(or a total of 61 Units can be networked). The address can be changed by a LAN
command (the factory default address is 1). The board uses a modified
version of the RS232 serial-data communication standard, where the
output-voltage (on pin I2, CN5) ranges from 0 to +5V (rather than the
usual -12V to +12V). In addition, this output pin is normally an open circuit;
and it will only output a serial TTL binary bit-stream when properly referenced
by its Node-Address. The serial data input-voltage (on pin I1, CN5) has
the standard range of -12V to +12V. The serial data-format is: 9600 Baud Rate, 1
Start-Bit, 8 Data-Bits, 1 Stop-Bit, and no Parity-Bit. These features allow the
creation of a Local Area Network (LAN) with up to 61 nodes (boards). A
typical 3-wire LAN with “Star Topology” is shown below. Note that the
control lines (G, I1, I2) with the same name are connected together (or
the boards are connected in parallel) and driven by an ASCII controller
(or PC), equipped with an RS232 serial port, operating at 9600 Baud rate.
on-board microprocessor provides the bus arbitration, required to avoid data
collisions on the 3-wire LAN bus. The
Si..Ne.. boards can be arranged in many
Local Area Network (LAN) topologies: Star, Daisy-Chain, etc. You may
create your own network or you may order one or more of
the Network Cable Assemblies listed below. Before you build your
network, click on this blue link and read this Application
Note: Sig-Note on Configuring a LAN-2 .
on the "Buy this
Product" Button or the Blue
Links Below to Buy the Optional Accessories
Si15NePITC2-HC12B-30V-2x16A, it is recommended to buy one
Digital Thermometer and one or more Network Accessories .
Si24DTsens-12B , 12-bit Digital Thermometer (
-550C to +1250C Range, in 0.0650C
12" leads and 3pin Molex Connector.
2 Line by 16 Character LCD with 12" long cable and 4-pin
1m long Network Cable Assembly with 9-pin female DB9
1m long Network Cable Assembly 9-pin female DB9
connector and a “Junction-Box” with 5 Phone Jacks.
1m long Network Cable Assembly with 6P4c Phone Plug
connector and a “Junction-Box” with 5 Phone Jacks.
We usually ship in 2-3 business
All Products Are Proudly Made in the USA