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Helios PD2-6100 Strain Gauge, Load Cell, and mV Meter 

Instruction Manual 

 

37 

 

Relay Operation Details 

Overview 

The four-relays option for the meter expands its 
usefulness beyond simple indication to provide users 
with alarm and control functions. Typical applications 
include high and low force, level, or pressure alarms, 
control applications such as simple on/off control, and 
relay alternation control for up to 4 pumps. There are 
four basic ways the relays can be used: 
1.  High and Low Alarms with Latching or Non-

Latching Relays 

2.  Simple On/Off Control with 100% Adjustable 

Deadband

 

3.  Sampling (Based on Time)

 

4.  Alternation Control for up to 4 Pumps

 

Relays Auto Initialization 

When power is applied to the meter, the front panel 
LEDs and alarm relays will reflect the state of the 
input to the meter. The following table indicates how 
the alarm LEDs and relays will react on power-up 
based on the set and reset points. 

 

Fail-Safe Operation 

The following table indicates how the relays behave 
based on the fail-safe selection for each relay: 

Fail-Safe 
Selection

 

Non-Alarm State

 

Alarm State

 

Power 
Failure

 

NO

 

NC 

NO

 

NC 

 

Off 

Open 

Closed 

Closed 

Open 

Relays 
go to 
non-
alarm 
state 

On 

Closed 

Open 

Open 

Closed 

Relays 
go to 
alarm 
state 

 

Note: NO = Normally Open, NC = Normally Closed. 

This refers to the condition of the relay contacts 
when the power to the meter is off. 

Front Panel LEDs

 

The alarm status LEDs on the front panel are 
available on all meters, even those without relays 
installed, and provide status indication for the 
following: 

LED

 

Status

 

1

 

Alarm 1

 

2

 

Alarm 2

 

3

 

Alarm 3

 

4

 

Alarm 4

 

 

The meter is supplied with four alarm points that 
include front panel LEDs to indicate alarm conditions. 
This standard feature is particularly useful for alarm 
applications that require visual-only indication. The 
LEDs are controlled by the set and reset points 
programmed by the user. When the display reaches a 
set point for a high or low alarm, the corresponding 
alarm LED will turn on. When the display returns to 
the reset point the LED will go off. The front panel 
LEDs respond differently for latching and non-latching 
relays. 
For non-latching relays, the LED is always off during 
normal condition and always on during alarm 
condition, regardless of the state of the relay (e.g. 
Relay acknowledged after alarm condition). 

For latching relays, the alarm LEDs reflect the status 
of the relays, regardless of the alarm condition. The 
following tables illustrate how the alarm LEDs function 
in relation to the relays and the acknowledge button 
(Default: F3 key assigned to ACK). 

 

Latching and Non-Latching Relay 
Operation 

The relays can be set up for latching (manual reset) 
or non-latching (automatic reset) operation. 

Relay terminology for following tables 

Terminology 

Relay Condition 

On 

Alarm (Tripped) 

Off 

Normal (Reset) 

Ack 

Acknowledged 

 

The On and Off terminology does not refer to the 
status of the relay’s coil, which depends on the fail-
safe mode selected. 
 

 

 

In latching relay mode, if Fail-Safe is off, latched 
relays will reset (unlatch) when power is cycled. 

 

 

Alarm # 

HI or LO 

Alarm 

Set 

Point 

Reset 

Point 

Power-

Up 

Reading 

Relay & 

LED 

HI 

1000 

500 

499 

Off 

LO 

700 

900 

499 

On 

LO 

250 

400 

499 

Off 

HI 

450 

200 

499 

On 

Summary of Contents for PD2-6100

Page 1: ...g Software SunBright Display Standard Feature Great for Outdoor Applications Operating Temperature Range 40 to 65 C 40 to 149 F Conformal Coated PCBs for Dust and Humidity Protection UL C UL Listed E1...

Page 2: ...te details Registered Trademarks All trademarks mentioned in this document are the property of their respective owners 2021 Precision Digital Corporation All rights reserved FREE MeterView Pro Program...

Page 3: ...nfiguration 17 Shunt Calibration 19 Relay Connections 19 Switching Inductive Loads 19 RS 485 Connections 20 RS 485 Multi Drop Connection 20 RS 485 Serial Converters 20 Digital I O Connections 21 F4 Di...

Page 4: ...put Aout 41 Reset Menu reset 41 Tare Menu Tare 41 Tare Functionality tare 41 Manual Control Menu Contrl 41 Setting Up the Password pass 42 Protecting or Locking the Meter 42 Making Changes to a Passwo...

Page 5: ...Strain Gauge Powered by External Supply 18 Figure 15 Multiple Strain Gauges Connected Through Junction Box 18 Figure 16 mV Transducer Input Connections 18 Figure 17 Four wire mV Transducer Connections...

Page 6: ...y loaded Helios PD2 6100 meter comes with four SPDT relays a 4 20 mA output one 10 VDC sensor excitation one 24 VDC power supply five digital inputs and four digital outputs and onboard RS 485 serial...

Page 7: ...Red Yellow Green Light Layers Button Mounted and Wired to Helios 1 Note 1 Specify MOD PD2LH model as a separate item on the order for the Helios to order the Light Horn Button accessory installed and...

Page 8: ...tal inputs Non Volatile Memory All programmed settings are stored in non volatile memory for a minimum of ten years if power is lost Power Options 85 265 VAC 50 60 Hz 90 265 VDC 20Wmax 12 24 VDC 12 24...

Page 9: ...esistive load 1 14 HP 50 W 125 250 VAC for inductive loads Noise Suppression Noise suppression is recommended for each relay contact switching inductive loads see Switching Inductive Loads on page 19...

Page 10: ...t to a 0 10 VDC output RS 485 Serial Communications Compatibility EIA 485 Connectors Removable screw terminal connector Max Distance 3 937 1 200 m max Status Indication Separate LEDs for Power P Trans...

Page 11: ...es located under the lower door panel and are accessible by removing the single securing screw Wires should be run through the knockout holes located on the bottom of the meter see Figure 5 Conduit Ho...

Page 12: ...e girth of the mounting screws pre drill holes at the mounting locations previously marked Insert mounting screws into the four mounting holes and screw them into the pre drilled holes DO NOT overtigh...

Page 13: ...o the top and bottom for vertical pipes or left and right for horizontal pipes of the reverse side of the meter enclosure using the provided fasteners DO NOT overtighten the fasteners as it could caus...

Page 14: ...Software Video at www predig com meterviewpro MeterView Pro Installation 1 Connect one end of the provided USB cable to the meter and the other end to the computer The computer will automatically inst...

Page 15: ...sor requires 5 VDC excitation the switch labeled P P must be configured accordingly To access the voltage selection switch 1 Turn off the power to the meter 2 Unscrew and open the lower door panel 3 L...

Page 16: ...f the lower door panel shows the location of all connectors available with the ordered configuration DO NOT connect any equipment to the RJ45 M LINK connector Otherwise damage will occur to the equipm...

Page 17: ...urned ON the Helios s power supply is used Range Switch 2 The range switch adjusts the gain of the internal circuitry Narrower ranges require more amplification OFF Range Lower internal gain Turn this...

Page 18: ...Connections The following figures show examples of strain gauge connections There is a 5 position DIP switch CONFIG to set up the input ranges and sensor excitation Note Refer to Switch Configuration...

Page 19: ...when switching inductive loads to prevent disrupting the microprocessor s operation The snubbers also prolong the life of the relay contacts Suppression can be obtained with resistor capacitor RC netw...

Page 20: ...meter 2 Press Up arrow until Serial SEriaL menu is displayed and press Enter Addres is displayed 3 Press Enter to change meter address using Right and Up arrow buttons Press Enter to accept 4 Press Me...

Page 21: ...al Input Connections A digital input F4 is standard on the meter This digital input should be connected with a normally open contact across F4 and COM or with an active low signal applied to F4 It can...

Page 22: ...activate the interlock relay This feature is enabled by configuring the relay and the corresponding digital input s see Setting Up the Interlock Relay Force On Feature on page 40 In the example below...

Page 23: ...set the meter input selection See Switch Configuration on page 17 to setup the switch Setup and programming is done using MeterView Pro or through the programming buttons After power and input signal...

Page 24: ...dvanced features of the meter Remote Buttons The meter can be operated via a remote control station PDA2364 MRUE using the digital input connections The PDA2364 MRUE mimics the Helios s four programmi...

Page 25: ...CAL 1 Scale 1 Enter the Scale menu for PV1 SCAL 2 Scale 2 Enter the Scale menu for PV2 Display Functions Messages Display Parameter Action Setting Description Cal Calibrate Enter the Calibration menu...

Page 26: ...Enter to reset min display Rst HL Reset high low Press Enter to reset max min displays Rst tr Reset tare Press Enter to reset tare tare Tare Enter Tare menu Captur Capture Press Enter to set meter to...

Page 27: ...ressing Enter Setting Numeric Values The numeric values are set using the Right and Up arrow buttons Press Right arrow to select next digit and Up arrow to increment digit value The digit being change...

Page 28: ...enu Setting the Display Units units Enter the pre defined engineering unit or custom unit The pre defined units have automatic conversion factors This unit will be displayed if d unit is selected as t...

Page 29: ...l point at all Pressing the Right arrow moves the decimal point one place to the right until no decimal point is displayed and then it moves to the leftmost position Pressing the Up arrow moves the de...

Page 30: ...the meter for at least 15 minutes before performing calibration to ensure specified accuracy Multi Point Calibration Scaling The meter is set up at the factory for 2 point linear calibration The numbe...

Page 31: ...error message is displayed the meter reverts to input 2 during calibration or scaling and to input 1 during internal calibration allowing the appropriate input signal to be applied or programmed The...

Page 32: ...g up the input and display press the Menu button to exit programming and skip the rest of the setup menu Press the Menu button again and the Up arrow to reach the Program menu and complete the scaling...

Page 33: ...ime g Off relay state controlled by Interlock feature 2 Set point 3 Reset point 4 Fail safe operation a On enabled b Off disabled 5 Time delay a On delay 0 999 9 seconds b Off delay 0 999 9 seconds Se...

Page 34: ...n safe limits and the relay coil is de energized when the alarm condition exists The fail safe operation is set independently for each relay Select on to enable or select off to disable fail safe oper...

Page 35: ...lay coil is energized in non alarm condition In case of power failure relay will go to alarm state Time Delay Operation The following graphs show the operation of the time delay function When the sign...

Page 36: ...ing Operation When the signal crosses the set point the relay trips and the sample time starts After the sample time has elapsed the relay resets The cycle repeats every time the set point is crossed...

Page 37: ...atus indication for the following LED Status 1 Alarm 1 2 Alarm 2 3 Alarm 3 4 Alarm 4 The meter is supplied with four alarm points that include front panel LEDs to indicate alarm conditions This standa...

Page 38: ...Manual reset any time Condition LED Relay Normal Off Off Alarm On On Ack Off Off Latching Relay with Clear Lt Clr In this application the meter is set up for manual reset only after the signal passes...

Page 39: ...Function 1 30 000 10 000 Controls pump 1 2 35 000 5 000 Controls pump 2 3 4 000 9 000 Controls low alarm 4 40 000 29 000 Controls high alarm Pump Alternation Operation 1 Pump 1 turns on when level re...

Page 40: ...lay Action menu and set the action to off 2 In the Advanced features User menu program any of the digital inputs to Force On any of the internal relays 1 4 3 Connect a switch or dry contact between th...

Page 41: ...select the tare mode There are three modes of operation Capture Tare Programmable Tare and Off Capture Tare Pressing the Tare key zeroes the display and the T indicator flashes indicating that tare is...

Page 42: ...on is pressed Press the Enter button while the message is being displayed and enter the correct password to gain access to the menu After exiting the programming mode the meter returns to its password...

Page 43: ...on Advanced Features Menu Display Messages Display Parameter Action Setting SCALE Scale Scaling parameter SCAL 1 Scale 1 Scaling parameter 1 SCAL 2 Scale 2 Scaling parameter 2 CutofF Cutoff Set low va...

Page 44: ...filter bypass may be set between 0 1 and 99 9 of full scale Rounding Feature round The rounding feature is used to give the user a steadier display with fluctuating signals Rounding is used in additi...

Page 45: ...e programmed with up to 8 linearization points Auto Zero Auto 0 Auto zero corrects for drift that can occur over time that causes the input signal to slowly change The meter will continue to read zero...

Page 46: ...ommended to use a milliamp meter with a resolution of at least 0 1 A to measure the output current The values saved internally during this procedure are used for scaling the 4 20 mA output in the Setu...

Page 47: ...ion as they have been programmed O Hold Hold current relay states and analog output as they are until a button assigned to enable relays Rly E is pressed d Hold Hold the current display value relay st...

Page 48: ...w input signal e g 0 00 mV and press Enter The display flashes for a moment while the meter is accepting the low input signal 5 After the display stops flashing a number is displayed with the leftmost...

Page 49: ...value or other parameters function assigned through the User menu Function Keys Operation During operation the programmable function keys operate according to the way they have been programmed in the...

Page 50: ...hrough all digits decimal points and relay indicators to enable the operator to check that all LEDs are functioning properly 4 Press the Enter button again to access the Information menu info or press...

Page 51: ...0 Relay 4 reset point RSt 4 35 00 Fail safe relay 1 Fls 1 Off Fail safe relay 2 Fls 2 Off Fail safe relay 3 Fls 3 Off Fail safe relay 4 Fls 4 Off Parameter Display Default Setting On delay relay 1 On...

Page 52: ...1 Input selected in Setup menu 2 Signal at Signal connector 3 Input exceeds range selected Display is unstable Check 1 Input signal stability and value 2 Display scaling vs input signal 3 Filter and b...

Page 53: ...8990 www predig com LIM2 6100_D SFT071 Ver 4 211 up 08 21 Contact Precision Digital Technical Support Call 800 610 5239 or 508 655 7300 Fax 508 655 8990 Email support predig com Sales Support Call 80...

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