-4-
Control Set Point
The set point value will be displayed whenever the
“SET” key is pressed. This value can be changed by
the following procedure:
Note: The units displayed, ºC, ºF, Hz, volts, mA or
ohms are established during the setup of the con-
troller. See F2 instructions on page 12 for changing
set point relay from reverse to direct acting.
Press both the “SET” key and the decrease “
È
” keys
simultaneously and hold for 3 seconds. The set point
value and a decimal point will appear, release both
keys. Wait approximately one second, then using the
decrease “
È
” key or increase “
Ç
” key, adjust the dis-
play to your new value. Depress the “SET” key to
enter your new value.
Note: If the “SET” key is not pressed within 5 sec-
onds, the new value will be lost and the set point value
will revert to its previous setting.
The controller will automatically return to the operat-
ing mode and display the current temperature.
Set Point and Features
Alarm Feature
Note: If the “SET” key is not pressed within 5 sec-
onds, the new value will be lost and the set point value
will revert to its previous setting.
The controller will automatically return to the operat-
ing mode and display the current temperature.
Sensor values that are out of range will generate an
error display. For Celsius: <-40ºC or >+538ºC. For
Fahrenheit: <-40ºF or >+1000ºF.
In the event of an improperly connected RTD sensor
or thermocouple, or if the control reads an “open”
circuit, the message “
HHH
” is displayed and the con-
trol de-energizes the control relay. In the event the
RTD sensor “shorts”, the message “
UUU
” is displayed
and the control de-energizes the control relay.
Note: Thermocouple “shorts” cause a new junction/
measurement point to be created. This will lead to
false readings and dangerous operating conditions.
If the calibration and setup information stored within
the memory becomes corrupt or erased, the control
will switch to its default calibration/configuration set-
tings. The display will flash the letter “
c
” on the left
side when default values are activated. The physical
size and position of the letter “
c
” will define the exact
nature of the problem.
Note: Shorted thermocouples will not result in an
error condition. Instead, incorrect readings will be
displayed.
A small “
c
” in the upper left-hand corner indicates the
control is relying on default (factory set)
calibration
values. This happens when the control is new and
has not yet been calibrated (setup).
A small “
c
” in the lower left-hand corner indicates the
control is relying on default
configuration
values. This
is a rare condition, but may occur if the control has been
calibrated for use with a two-wire RTD sensor but the
configuration parameters have not been changed from
their default values. Changing any of the configuration
or set point variables will turn off this indication.
A large “
C
” on the left side of the display indicates the
control is using the default values for the configura-
tion and the calibration. This can occur in a new con-
trol that has never been calibrated or configured, or in
a control wherein the memory has been erased.
Error Conditions
Error Messages
Note: This is not a safety device.
The Alarm feature, which is enabled using the “
F3
” set-
ting during setup (see page 13), allows the user to
establish a set point above which the control will enter
into an alarm condition. This set point should be higher
than the set point setting on the control. During the
alarm condition the control relay will de-energize the
set point relay and flash “
AAA
” on the display.
After enabling this feature, you may view and adjust
the “
ALARM SET POINT
” on the display. The alarm
set point value will be displayed and can be adjusted
by pressing the “SET” key and the increase “
Ç
” key
simultaneously and holding them for approximately
three seconds. The alarm set point value will appear
as a flashing display.
Note: If the “SET” key is not pressed within 5 sec-
onds, the new value will be lost and the set point value
will revert to its previous setting.
To change the “ALARM SET POINT”, press the increase
“
Ç
” or decrease “
È
” keys while the display is flashing.
Press the “SET” key to enter your new value. If you
wish to accept the current value, press the “SET” key.
-11-
U1, Sensor Type
U2, Signal Offset
This setting tells the DE20 control what type of sensor it is using.
Value
Board #
Sensor Type
Sensor Description
1
5413
2-wire RTD
Platinum RTD, TCR 0.00385 ohm/ohm/ºC
2
5413
2-wire RTD
Platinum RTD, TCR 0.00392 ohm/ohm/ºC
3
5415
3-wire RTD
Platinum RTD, TCR 0.00385 ohm/ohm/ºC
4
5415
3-wire RTD
Platinum RTD, TCR 0.00392 ohm/ohm/ºC
5
5417
Thermocouple
J-Type Iron-Constantan NIST Monograph 175 REV ITS-90
6
5417
Thermocouple
K-Type Chromel-Alumel NIST Monograph 175 REV ITS-90
7
5417
Thermocouple
T-Type Copper-Constantan NIST Monograph 175 REV ITS-90
8
5417
Thermocouple
R-Type Platinum, 13% Rhodium-Platinum NIST Monograph
175 REV ITS-90
9
5415
Voltage
Potential signal (1.0 to 10.0 V)
10
5415
Current
Current signal (4.00 to 20.00 mA)
11
5415
Frequency
Pulse train frequency (0 to 200 Hz, counts per second)
12
5415
Resistance
Pure resistance signal (0 to 1000 ohms)
Note: The 5415 sensor board will also accept 2 wire RTDs. The default sensor type setting is “1” (1000
ohm 2 wire RTD). When using the 5415 sensor board, an “on-board” DIP switch must also be configured,
see page 13.
This setting, which may be any number from -9 to +9, represents an offset value which is applied to the signal
received from the sensor. The units (ºC, ºF, ohms, etc.) will be dictated by the type of sensor selected in “
U1
” settings.
Temperature Sensor -
Number represents degrees Celsius or Fahrenheit as
determined by the “F5” setting
Voltage Sensor -
Number represents tenths of a volt (0.1 VDC)
Current Sensor -
Number represents hundredths of milliamps (0.01 mA)
Resistance Signal Devices -
Number represents ohms.
Frequency Signal Devices -
This setting will have no effect.
Not available.
This setting, which may be any number from 1 to 64, represents the number of samples taken from the
sensor and maintained in memory. These samples are then averaged to provide an active filter of the signal.
Using a small value for this setting will cause the DE20 control to respond more quickly to sudden changes
in the sensor signal level, but this also causes the unit to be more susceptible to EMI/RFI noise. As this value
is increased, the susceptibility to inference is reduced.
The default value for this setting is four (4).
Note: When sensing temperature with a 100 ohm RTD (2 or 3 wire), set this value to twenty (20) to reduce
control error.
When sensing frequency signal, this setting establishes the time period for the controller to wait for a pulse
signal. Use two (2) for this value when measuring frequency. This causes the control to measure frequencies
as low as 1 hertz while updating the display once every two seconds.
U3, Outpul Signal Offset
U4, Signal Filter
M-33-01-02 02/17/11
M-33-01-02 02/17/11
U
U
U
U
U
!
