Dwyer Instruments DHII Digihelic II Series Installation and operating instructions

Bulletin B-31
Series DHII Digihelic®II Differential Pressure Controller
Specifications - Installation and Operating Instructions
DWYER INSTRU ENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • ICHIGAN CITY, IN 46360, U.S.A. Fax: [phone] e-mail: [email protected]
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1
DI ENSIONS
!
1-1/2
[38.35]
1-45/64
[43.18]
2-23/64
[59.94]
1-31/64
[37.62]
4-23/32
[120]
4-23/32
[120]
3-7/16
[87.12]
1-5/16
[33]
1-17/32
[38.61] 45/64
[17.78]
1-1/16
[26.97]
1-7/8
[47.5]
1-45/64
[43.18]
MOUNTING HOLE
PATTERN
4X Ø3/16 [4.76]
CLEARANCE HOLES FOR
MOUNTING
3-17/64
[83]
4-1/8
[105]
WIRING TER INAL ACCESS
!
5-7/32
[132.56]
4-9/64
[105.17]
#8 LOCK WASHER
8-36 FLAT HEAD SCREWS
DO NOT REMOVE
THESE SCREWS
TO GAIN ACCESS TO WIRING TERMINALS,
REMOVE THESE TWO SCREWS AND “FLIP” DISPLAY
90° DO NOT REMOVE THE SCREWS WITH]
POWER APPLIED TO INSTRUMENT
HINGED
STANDOFF
WIRING
TERMINALS
OPTIONAL A-438 BRACKET
OUNTING DIAGRA
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2
SPECIFICATIONS
Service: Air and non-combustible, compatible gases.
Wetted aterials: Consult factory.
Housing aterial: Aluminum, glass.
Accuracy: ±0.5% at 77°F (25°C) including hysteresis and repeatability (after 1 hour warm-up).
Stability: < ±1% per year.
Pressure Limits: Ranges ≤ 2.5 in. w.c. = 2 psi
5˝: 5 psi; 10˝: 5 psi; 25˝: 5 psi; 50˝: 5 psi; 100˝: 9 psi.
Temperature Limits: 32 to 140°F (0 to 60°C).
Compensated Temperature Limits: 32 to 140°F (0 to 60°C).
Thermal Effects: 0.020%/°F (0.036/°C) from 77°F (25°C).
Power Requirements:
High Voltage Power = 100 to 240 VAC, 50 to 400 Hz or 132 to 240 VDC;
Low Voltage Power = 24 VDC ±20%.
Power Consumption:
Low Voltage Power = 24 VDC - 130 mA max.
High Voltage Power = 100 to 240 VAC, 132 to 240 VDC - 7VA max.
Output Signal: 4-20 mA DC into 900 ohms max.
Zero & Span Adjustments: Accessible via menus.
Response Time: 250 ms (dampening set to 1).
Display: 4 digit backlit LCD 0.6˝ height. LED indicators for set point and alarm status.
Electrical Connections: Euro type removeable terminal blocks with watertight conduit fittings for
1/2˝ watertight conduit.
Process Connections: 1/8 female NPT.
Enclosure Rating: Designed to meet NEMA 4 ( P66).
ounting Orientation: Mount unit in vertical plane.
Size: 4.73˝ x 4.73˝ x 3.43˝ (120 mm x 120 mm x 87.1 mm).
Weight: 2 lb 10 oz (1.19 kg).
Serial Communications: Modbus®RTU, RS485, 9600 Baud.
Agency Approvals: UL & CE.
SWITCH SPECIFICATIONS
Switch Type: 2 SPDT relays.
Electrical Rating: 8 Amps at 240 VAC resistive.
Set Point Adjustment: Adjustable via keypad on face.
Modbus®is a registered trademark of Schnieder Automation.
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3
Notes:
1. The instrument may be powered from the AC line or 24 VDC. Do not wire AC line terminals 1-2 on
the lower board and 24 VDC terminals 4-5 on the upper board at the same time or damage to the
unit will result.
2. For supply connections, wire in accordance with an equivalent national standard or code. Use
copper conductors only rated for at least 75°C.
3. Terminals on upper board are rated CLASS 2.
4. ISOLATION:
Relays - 1500 VAC to all other inputs and outputs.
AC Line Power (terminals 4-5) - 1500 VAC to all other inputs and outputs.
RS485 output - 500 VAC to all other CLASS 2 wiring.
The 24 VDC Power, 4-20 mA transmitter, and Remote Reset Switch share a common
ground.
5. The Remote Reset Switch must be a dry contact switch.
6. Shielded cable is required for RS485 wiring.
WIRING
WARNING
f Digihelic® Controller is powered by 24 VDC, the device receiving the 4-20 mA
transmitter output MUST NOT share a common ground with the 24 VDC supply or
damage to the Digihelic® Controller will result.

1122334455667
788112 23
34455667788
CONNECTORCONNECTOR ONON
LOWERLOWER BOARDBOARD
CONNECTORCONNECTOR ONON
UPPERUPPER BOARDBOARD
100-240100-240 VACVAC oror
132-240132-240 VDCVDC POWERPOWER
NOTENOTE 11
3/83/8 AA250vac250vac
MEDIUMMEDIUM LAGLAG
N/CN/C N/CN/C
N/ON/O N/ON/O
C
CCC
SP1SP1
RELAYRELAY
SP2SP2 OROR
ALARMALARM
RELAYRELAY
A-A-
B+B+
RS485RS485 SERIALSERIAL
COMMUNICATIONCOMMUNICATION
++
-
-
2424 VDCVDC POWERPOWER
NOTENOTE 11
REMOTEREMOTE RESETRESET
SWITCHSWITCH
DeviceDevice receivingreceiving 4-20mA4-20mA
signal.signal. CheckCheck specicationsspecications
ofof thisthis devicedevice forfor inputinput loadload
resistance.resistance. TypicalTypical 250250 toto
600600 OHMS,OHMS, 900900 OHMSOHMS
maximum.maximum.
++
--
4-20mA4-20mA
TRANSMITTERTRANSMITTER
OUTPUTOUTPUT
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4
When wiring the instrument, you must follow industry standard practice for control and
protection against Electro-Static Discharge (ESD). Failure to exercise good ESD practices
may cause damage to the control.
WIRING
1. Remove cover.
2. To gain access to the wiring terminal blocks, remove the upper and lower screws toward the center
of the display board, and then flip the display board up at a 90° angle.
3. Wire to the two terminals blocks as shown in the wiring diagram.
Note: Depending on the application, it may be only necessary to wire to the smaller terminal block on
the upper board. n that case one of the liquid tight fittings may be removed and replaced with the
provided rubber plug.
4. For liquid tight applications, use only 1/2˝ liquid tight conduit.
5. When wiring is complete, reverse steps 2 and 1. Make sure the cover is properly tightened to the
housing.
INSTALLATION
Mount the instrument in a location that will not be subject to excessive temperature, shock or vibration.
Pressure Connections
Use 1/8 male NPT fittings. When tightening fittings, grasp the brass fitting on the Digihelic® Controller
with a 1/2˝ wrench to prevent the fitting on the Digihelic® Controller from turning.
꟣
DIGIHELIC® II CONTROLLER RS485 WIRING
SHIELDSHIELD SHIELDSHIELD
TIETIE SHIELDSHIELD TOTO EARTHEARTH GROUNDGROUND
TOTO RS232RS232 TOTO
RS485RS485 CONVERTERCONVERTER
120120 OHMOHM
RESISTORRESISTOR
LASTLAST UNITUNIT ONON RS485RS485 BUSSBUSS
WIREWIRE NUTNUT
DIGIHELICDIGIHELIC --RS485RS485 WIRINGWIRING TOTO DAISYDAISY CHAINCHAIN INSTRUMENTSINSTRUMENTS ONON THETHE RS485RS485 BUSSBUSS
UPUP TOTO 128128 UNITSUNITS MAYMAY BEBE DAISYDAISY CHAINEDCHAINED
THETHE 120120 OHMOHM RESISTORRESISTOR
ISIS USUALLYUSUALLY ONLYONLY
NECESSARYNECESSARY FORFOR LONGLONG
WIREWIRE RUNS.RUNS.
1
122334455667
7881
12
23
34455667
788
CONNECTORCONNECTOR ONON
LOWERLOWER BOARDBOARD
CONNECTORCONNECTOR ONON
UPPERUPPER BOARDBOARD
112233445
56
6778
8112233445566778
8
CONNECTORCONNECTOR ONON
LOWERLOWER BOARDBOARD
CONNECTORCONNECTOR ONON
UPPERUPPER BOARDBOARD
1
1223344556
6778
81
1223
34455667
788
CONNECTORCONNECTOR ONON
LOWERLOWER BOARDBOARD
CONNECTORCONNECTOR ONON
UPPERUPPER BOARDBOARD
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5
SP/ALSP/AL
MENUMENU
EE
RSTRST
HO E POSITION FUNCTION
Sequences the display
through SET PO NT and
ALARM settings
Allows access to the menus
Displays full scale range of
unit
Clears or resets an Alarm
(alarm set for manual reset)
AIN ENU FUNCTION
Return to home position
Return to home position
Sequences through
menus
Sequences through
menus
Enter into SUB MENU
SUB ENU FUNCTION
Return to home position
Return to previous
menu
ncrements a value
Decrements a value
Changes a value or
setting. Press ENTER
and display will blink.
Adjust with UP or
DOWN arrows. Press
ENTER to store. Display
will stop blinking.
Peak/Valley SUB
MENU resets display
to present value.
SP/AL
MENU
UP
ARROW
ENTER
RESET
KEY FUNCTIONS
SP1SP1 SP2SP2 ALHIALHI
ALLOALLO
SCFMSCFM
99.9999.99
X1K
SP/ALSP/AL RSTRST
MENUMENU EE
MULTIPLIERMULTI PL IE R DESCRIPTORDESCRIPTOR
VISIBLEVISIBLE WITHWITH SOMESOME VELOCITYVELOCITY
ANDAND FLOWFLOW RANGESRANGES FRONTFRONT PANELPANEL
UNITSUNITS
PROCESSPROCESS
VALUEVALUE
HIGHHIGH ALARMALARM
DESCRIPTORDESCRIPTOR
LOWLOW ALARMALARM
DESCRIPTORDESCRIPTOR
SP1SP1
DESCRIPTORDESCRIPTOR
SP2SP2
DESCRIPTORDESCRIPTOR
DOWN
ARROW
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6
SETTING SET POINTS AND ALAR S
The hot key provides direct access to the Set Point and Alarm MENU. The Set Point and Alarm
MENUS that are displayed are based upon the Control (CtrL) SUB MENU.
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL
Visible whenVisible when
Visible whenVisible when
Visible whenVisible when
mode =mode =
mode =mode =
mode =mode =
CONTROL MODECONTROL MODE CONTROL MODECONTROL MODE
CONTROL MODECONTROL MODE
SET POINT ADJUST ENT
Adjusting the Digihelic® Controller Set Points is quick and simple. nstead of setting a set point and
deadband, simply adjust SP1H or SP2H for the desired relay turn on point, and then adjust SP1L or SP2L
for the desired relay turn off point.
PRESSURE PRESSURE
00
00TIMETIME
0.20.2
0.40.4
0.60.6
0.80.8
1.0
(in. w.c.)
n the above graph, an instrument with a 1.0˝ range would have the SP1 relay turn on at 0.8˝ and off
at 0.4˝. SP1H sets the relay turn on point, and SP1L sets the relay turn off point. The relays outputs
normally function in the direct acting mode, which means the relays turn on with an increase in
pressure. SP1 may be configured to act as a reverse acting relay (refer to the 1SP SUB MENU setting,
page 15). When set for reverse acting, SP1H sets the relay turn OFF point, and SP1Lsets the relay turn
ON point. SP2 is always direct acting.
SP/ALSP/AL
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7
MENU MAPMENU MAP
CONTINUED
CONTINUED
SETTINGSSETTINGS
MAIN MENUS SUB MENUS
MENUS
UNAVAILABLE
FOR
BI-DIRECTIONAL
RANGES AND
RANGES ABOVE
25 IN. W.C.
EE
MENUMENU
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8
CONTINUEDCONTINUED
SETTINGSSETTINGS
MAIN MENUS SUB MENUS
EE
MENUMENU
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9
MAIN MENUS SUB MENUS SETTINGS
Menus present only
in pressure operation
EE
MENUMENU
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10
ain enu Selections (Upper Right Display Reads MENU )
SECr Security - Lock out access to Set Point and Alarm settings, or lock out access to all
settings.
OPEr Operation - Selection of Pressure, Velocity or Flow and corresponding engineering units.
OUt Output - Select a Single Set Point, 2 Set Points, or a Set Point and an Alarm mode of
operation.
d.S Display - Monitor and adjust display related settings: Peak, Valley, display resolution, %
output and dampening.
AdU Advanced functions - Modify advanced function parameters, transmitter output scaling,
Modbus®communication settings, Maintenance Set Point settings and calibration.
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11
AIN ENUS and SUB ENUS
SECr (Security) AIN ENU
SECr is the only SUB MENU in the security MENU. When the security SUB MENU is selected,
the present security level is displayed in the upper right hand display. To change the
security level, adjust the number displayed to the number shown in the following table for
the desired security level.
The password values shown in the table cannot be altered, so retain a
copy of these pages for future reference.
OPEr (Operation) AIN ENU
The OPEr MENU selects the measurement type of the instrument.
The SUB MENUS are:
PrES - Pressure KFAC - K Factor XDIM - X Dimension
UEL - Velocity ArEA - Area YDIM - Y Dimension
FLO - Flow DIA - Diameter
f the instrument is set for Velocity, the OPEr MENU will have an additional KFAC SUB MENU. f the
instrument is set for Flow, the OPEr MENU will have additional KFAC and ArEA SUB MENUS. These
will be discussed under Velocity and Flow. When scrolling through the OPEr SUB MENUS, the
measurement type the unit is currently set for will show the units in the upper right display. The other
measurement types will have a blank upper right display.
Security Level Displayed
1
2
3
4
Access
All menus access
Menu Access
SP/AL Locked
SP/AL Access
Menus Locked
All settings locked
Password Value to Enter
10
70
90
111
Units visible, so unit
is presently set to
measure pressure
is presently set to
measure pressure
Units not visibleUnits not visible Units not visibleUnits not visible
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12
PrES (Pressure) SUB ENU
For pressure measurement, the following units are available:
Table 1 Pressure Range vs. Available Units
INWC
.1000
.2500
.5000
1.000
2.500
5.000
10.00
25.00
50.00
100.0
FTWC
.2083
.4167
.8333
2.083
4.167
8.333
WC
2.540
6.350
12.70
25.40
63.50
127.0
254.0
635.0
1270
2540
C WC
.2540
.6350
1.270
2.540
6.350
12.70
25.40
63.50
127.0
254.0
PSI
.1806
.3613
.9032
1.806
3.613
INHG
.1839
.3678
.7356
1.839
3.678
7.356
HG
.1868
.4671
.9342
1.868
4.671
9.342
18.68
46.71
93.42
186.8
BAR
.2491
.6227
1.245
2.491
6.227
12.45
24.91
62.27
124.5
249.1
PA
24.91
62.27
124.5
249.1
622.7
1245
2491
6227
KPA
.1245
.2491
.6227
1.245
2.491
6.227
12.45
24.91
HPA
.2491
.6227
1.245
2.491
6.227
12.45
24.91
62.27
124.5
249.1
OZIN
.1445
.2890
.5780
1.445
2.890
5.780
14.45
28.90
57.80
UEL (Velocity) SUB ENU
For velocity measurement, the following units are available:
SFPM - Standard feet per minute
M/S - Meters per second
Table 2 Available Velocity Ranges
Note: Air velocity and flow readings are based upon standard dry air conditions with an ambient
temperature of 70°F and a barometric pressure of 29.92 NHG.
INPUT RANGE INWC
0 - 0.1
0 - 0.25
0 - 0.5
0 - 1
0 - 2.5
0 - 5
0 - 10
0 - 25
SFP RANGE
0 - 1266
0 - 2002
0 - 2832
0 - 4004
0 - 6332
0 - 8954
0 - 12.66 x K
0 - 20.02 x K
/S RANGE
0 - 6.431
0 - 10.17
0 - 14.39
0 - 20.35
0 - 32.17
0 - 45.48
0 - 64.33
0 - 101.7
INWC - nches of water column
FTWC - Feet of water column
MMWC - Millimeters of water column
CMWC - Centimeters of water column
PSI - Pounds per square inch
INHG - nches of mercury
MMHG - Millimeters of mercury
MBAR - Millibar
PA - Pascal
KPA - Kilopascals
HPA - Hectopascals
OZIN - Ounce inches
Note: OVFL(over flow) or UnFL(under flow) will appear when the ranges have been exceeded above
or below full scale by 2%.
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13
FLO (Flow) SUB ENU
For flow measurements the following units are available:
SCFM - Standard cubic feet per minute
M 3H - Cubic meters per hour
FLO r (Flow Range) SUB ENU
LO - 99.99 x 1K flow range
HI - 999.9 x 1K flow range
Tables 3 -6 show the flow ranges available, and the maximum duct size that can be set for each input
range.
Table 3
FLOr = LO aximum Duct Size (English)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
SCF
RANGE
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
AX. DUCT
SIZE, SQ. FT.
78.9
49.9
35.3
24.9
15.7
11.1
7.8
4.9
KFAC SUB ENU
KFAC K Factor - becomes accessible if the instrument is set for Velocity or Flow.
When the Digihelic® Controller is used with a pitot tube, the manufacturer may specific a K Factor.
The adjustment range is 0.01 to 2.00. The factory setting is 1.
Table 4
FLOr = HI aximum Duct Size (English)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
SCF
RANGE
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
AX. DUCT
SIZE, SQ. FT.
789.8
499.5
353.1
249.7
157.9
111.7
78.9
49.9
Table 5
FLOr = LO aximum Duct Size ( etric)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
ˆ3/Hr
RANGE
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
AX. DUCT
SIZE ˆ2
4.32
2.73
1.93
1.37
0.86
0.61
0.43
0.27
Table 6
FLOr = HI aximum Duct Size ( etric)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
ˆ3/Hr
Range
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
AX. DUCT
SIZE, ˆ2
43.19
27.31
19.3
13.64
8.63
6.10
4.31
2.73
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14
ArEA, DIA, XDIM and YDIM SUB ENUS
These SUB MENUS become accessible if the instrument is set for flow. When measuring flow, the
area of the duct must be specified. Tables 3 and 4 show the input range vs maximum flow and duct
size. For a rectangular duct the maximum size is specified in square feet or meters. For a circular duct
the maximum size is specified as the diameter. X, Y and circular dimensions are entered in feet with
0.01 foot resolution for FLOr = LO and 0.1 foot resolution for FLOr = HI, or entered in millimeters with
1 millimeter resolution.
ArEA - Area, select CIR for a circular duct or RECT for a rectangular duct. f a circular duct
is selected, the DIA SUB MENU will be activated. f a rectangular duct is selected, the XDIM
and YDIM SUB MENUS will be activated.
DIA - Diameter, enter the diameter of a duct
XDIM - Enter the “X” dimension of a duct
YDIM - Enter the “Y” dimension of a duct
OUt (Output) AIN ENU
The OUt MENU selects the output type of the instrument. The SUB
MENUS are:
CtrL- Control type ALrE - Alarm reset, manual or auto
ISP - SP1 reverse or direct acting AL.H - Alarm inhibit
AL - Alarm type ALDL - Alarm delay
Y
X
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15
0
100
Process
Reverse Acting
Time
SPH
SPL
Relay Inactive
Relay Active
CtrL (Control) SUB ENU
1SP - Single set point
2SP - Two fully independent set points
SPAL - Single set point and alarm
1SP (SP1 Reverse or Direct Acting) SUB ENU
DIR - Direct. Relay turns on with increasing pressure
REV - Reverse. Relay turns on with decreasing pressure
0
100
Process
Direct Acting
Time
SPH
SPL
Relay Inactive
Relay Active
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16
The following alarm function SUB MENUS are activated when CtrL is set to SPAL :
AL (Alarm Type) SUB ENU
HI - High alarm
LO - Low alarm
HILO - For a high/low guardband type alarm
ALAR ADJUST ENT
Alarm settings are dependent upon the selected alarm mode. The Digihelic® Controller alarm may
be configured as a High Alarm, Low Alarm, or High/Low Alarm. Alarm settings are all absolute and may
be set to anywhere within the range of the instrument. The dead bands of the alarms are fixed at 1%
of full scale.
MIN. PRESSURE MAX. PRESSURE
ALHI
Relay OFF Relay ON
HIGH ALARM FUNCTION
MIN. PRESSURE MAX. PRESSURE
ALLO
Relay ON Relay OFF
LOW ALARM FUNCTION
MIN. PRESSURE MAX. PRESSURE
ALLO
Relay ON Relay OFF Relay ON
HIGH/LOW ALARM
FUNCTION
ALHI
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17
ALrE (Alarm Reset) SUB ENU
ONOF- Automatic reset
HOLD - Manual reset. An alarm is reset by the RESET key on the front panel, or an external
reset switch.
AL.H (Low Alarm Inhibit) SUB ENU
ON - Alarm inhibit is on
OFF - Alarm inhibit is off
f AL.H is selected ON, a low alarm condition is suspended upon power up until the process
value passes through the alarm set point once.
ALDL (Alarm Delay) SUB ENU
Sets the amount of time an alarm condition must be continuously met before the alarm
condition is recognized. The alarm delay is adjustable from 0-3600 seconds.
d.S (Display) AIN ENU
PEAK - Peak value rESO - Resolution
VALy - Valley value Pd.S - Process display
ZERO - Zero DAMP - Dampening level
PEAK (Peak) SUB ENU
The Peak feature stores the highest pressure reading the instrument has measured since the
last reset or power up. At power up PEAK is reset to the present pressure reading. To manually
reset the PEAK value, press the RESET key while in the PEAK SUB MENU.
VALy (Valley) SUB ENU
The valley feature stores the lowest pressure reading the instrument has measured since the
last reset or power up. At power up VALy is reset to the present pressure reading. To
manually reset the VALy value, press the RESET key while in the VALy SUB MENU.
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18
rESO (Resolution) SUB ENU
The Digihelic® Controller is capable of displaying four digits of resolution. However, at very low
pressures the instability of the pressure may cause fluctuations in the least significant digit
causing the least significant digit to be of little value.
Three digit resolution (3DIG) can only be active when there is at least one digit to the right of a
decimal.
3DIG - Set display for 3 digit resolution
4DIG - Set display for 4 digit resolution
Pd.S (Process Display) SUB ENU
STD - Display reads pressure, velocity, or flow values
PCT - Display reads % of full scale value
When the display is reading percent, PCT is displayed in the upper right of the display. The
percent display is only available in pressure operation.
DAMP (Dampening) SUB ENU
Adjust from 1-16
Dampening stabilizes the display from instabilities due to things such as vibration and
excessive pressure fluctuations. The dampening setting adjusts the amount of readings that
are averaged for each display update. Adjust the dampening value until the display reads a
stable value for the application.
AdU (Advanced) AIN ENU
POL - Process output low ADDR - Modbus® address
POH - Process output high WR - Modbus®write enable/disable
MSP1 - Maintenance set point 1 ZERO - Zero calibration
MSP2 - Maintenance set point 2 SPAN - Span calibration
POL and POH (Process Output Low and High) SUB ENUS
This feature is used in pressure operation only.
Process output low and high are used to scale the 4-20 mA output. Set POL to the desired
display reading for 4mA output, and set POH to the desired display reading for 20 mA output.
POH must be higher than POL. POL may be adjusted 2% BELOW minimum scale up to POH.
POH may be adjusted from POL to 2% ABOVE maximum scale.
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MSP1 and MSP2 ( aintenance Set Point 1 & 2) SUB ENUS
Adjust for the desired maintenance set points when the unit is placed in the maintenance
mode. The deadband is fixed at 2% of full scale. To enter or leave the maintenance mode,
press and hold the for 8 seconds.
ADDR ( odbus® Address ) SUB ENU
Modbus®communication instrument address. Set from 1 to 247. This number must match the
address number used by the host computer.
To obtain the Digihelic® Controller Modbus®register list please visit www.dwyer-inst.com
See page 4 for wiring diagram.
WR ( odbus® Write Protect) SUB ENU
d.S - Disables write commands from Modbus®. Modbus®can only read information from the
instrument.
En - Enable write commands from Modbus®. Modbus®can read information from and write
information to the instrument.
ZERO and SPAN (Calibration of Zero and Span) SUB ENUS
The lower display reads CAL in this mode.
ZERO Calibration
Note: For accurate calibration, DO NOT apply any pressure when performing this function.
With the display reading ZERO, press the ENTER key. The upper display will blink. Press
ENTER again to complete the zeroing of the instrument or press the MENU key to cancel.
SPAN Calibration
With the display set to SPAN, apply full scale pressure to the unit. Press the ENTER key. The
upper display will blink. Press ENTER again to complete the calibration or press the MENU key
to cancel.
SP/ALSP/AL
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P.O. BOX 373 • ICHIGAN CITY, IN 46360, U.S.A. Fax: [phone] e-mail: [email protected]
www. .com [e-mail]1.800.561.8187