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PD6720 Field-Mount Loop-Powered Rate/Totalizer 

Instruction Manual 

 

5

 

Specifications 

Except where noted all specifications apply to operation at +25°C. 

General 

Display 

Five digits 
(-9999 to 
99999) 

0.70" (17.8 mm) high,  
7-segment, automatic lead zero 
blanking.  

Seven 
characters 

0.4" (10.2 mm) high, 14-segment. 

Symbols 

High & Low Alarm, Password Lock 

Display 
Orientation 

Display may be mounted at 90° increments  
up to 270° from default orientation. 

Display 
Assignment 

Upper display is assigned to rate and lower  
display may be assigned to total, tag name/ 
engineering units, or to alternate between them. 

Display 
Update Rate 

Ambient > -25°C: 2 Updates/Second  
Ambient < -25°C: 1 Update/5 Seconds 

Backlight 

White; Loop-powered or externally powered. 
Backlight can be enabled or disabled via 
alternative wiring of terminal block. Loop-
powered backlight brightness will increase as 
the input signal current increases. Externally 
powered backlight has consistent brightness. 

Externally 
Powered 
Backlight 

Voltage 
Range: 

Maximum Power 

9-36 
VDC 


VDC 

12 
VDC 

24 
VDC 

36 
VDC 

 

0.2 W

 

0.25 W

 

0.5 W

 

0.75 W

 

 

Display 
Overrange  

Display flashes 

99999

 

Display 
Underrange 

Display flashes 

-9999

 

Programming 
Method 

Four SafeTouch through-window buttons  
when cover is installed. Four internal  
pushbuttons when cover is removed. 

Noise Filter 

Programmable 

LO

,

 

med

,

 

HI

, or 

OFF

 

Recalibration 

Recalibration is recommended at least every 
12 months. 

Max/Min 
Display 

Max/Min readings reached by the process  
are stored until reset by the user or until  
power to the meter is turned off.  

Advanced 
Function 

Linear, square root, or programmable  
exponent 

Password 

Programmable password restricts  
modification of programmed settings. 

Non-Volatile 
Memory 

All programmed settings are stored in  
non-volatile memory for a minimum of  
ten years if power is lost. 

Normal Mode 
Rejection 

64 dB at 50/60 Hz 

Environmental 

Operating temperature range: -40 to 75°C 
Storage temperature range: -40 to 75°C 
Relative humidity: 0 to 90% non-condensing 

Connections 

Screw terminals accept 12 to 22 AWG wire 

Enclosure 
 

NEMA 4X, IP65 plastic field enclosure  
Color: grey 
Three ¾" NPT threaded conduit openings.  
Two ¾" NPT plastic conduit/stopping plug with  
1.29" wrenching flats and screwdriver slot. 

Mounting 

May be mounted directly to conduit. Two slotted 
flanges for wall mounting or NPS 1½" to 2½" or 
DN 40 to 65 mm pipe mounting.  
Se

Dimensions

 on pag

7

. 

Overall 
Dimensions 

5.67" x 5.25" x 4.18" (W x H x D) 
(144 mm x 133 mm x 106 mm) 

Weight 

1.65 lbs (26.4 oz, 0.75 kg) 

Warranty 

3 years parts and labor. See Warranty  
Information and Terms & Conditions on 

www.predig.com

 for complete details. 

Input 

Input   

4-20 mA 

Accuracy  

±0.03% of calibrated span ±1 count, 
square root & programmable exponent 
accuracy range: 
10-100% of calibrated span. 

Temperature Drift 

50 PPM/

C from -40 to 75

C ambient 

Maximum Voltage 
Drop & 
Equivalent 
Resistance 

Without Backlight 
or with Externally  
Powered Backlight

 

With Loop-
Powered 
Backlight

 

3.0 VDC @ 20 mA

 

6.0 VDC @ 20mA

 

 

150 

Ω @ 20 mA 

300 

Ω @ 20 mA 

Multi-Point  
Linearization 

2 to 32 points 

Signal Input 
Conditioning 

Linear, square root, programmable 
exponent 

Programmable  
Exponent 

User selectable from 1.0001 to 2.9999 
for open channel flow. 

Low Flow Cutoff 

0-99999 (0 disables cutoff function)  
Point below at which display always 
shows zero. 

Decimal Point 

User selectable decimal point 

Minimum Span 

Input 1 & Input 2: 0.10 mA 

Calibration  
Range 

An 

Error

 message will appear if input 1 

and input 2 signals are too close 
together. 

Input 
Range

 

Minimum Span 
Input 1 & Input 2

 

4-20 mA 

 

0.10 mA 

 

Input Overload 

Over current protection to 2 A max. 

HART 
Transparency 

The meter does not interfere with 
existing HART communications; it 
displays the 4-20 mA primary variable 
and it allows the HART 
communications to pass through 
without interruption. 
The meter is not affected if a HART 
communicator is connected to the loop. 
The meter does not display secondary 
HART variables. 

 

 

 

Summary of Contents for PD6720 Series

Page 1: ...Display Rate in Units per Second Minute Hour or Day Display Open Channel Flow with Programmable Exponent Feature Open Collector Pulse or Alarm Output Display Mountable at 0 90 180 270 SafeTouchTM Thro...

Page 2: ...Terms Conditions on www predig com for complete details 2020 Precision Digital Corporation All rights reserved Introduction The PD6720 is a rugged field mount loop powered rate totalizer fully featur...

Page 3: ...ime Base t base 15 Setting the Total Conversion Factor totCF 15 Manual or Automatic Total Reset Function t rST 16 Setting the Tag Display tag 16 Setting Up the Password PASSWRD 17 Locking the Meter 17...

Page 4: ...Enclosure Dimensions Side Cross Section View 7 Figure 3 Connector Board 8 Figure 4 Connections without Backlight 9 Figure 5 Connections with Loop Powered Backlight 9 Figure 6 Connections with Externa...

Page 5: ...Environmental Operating temperature range 40 to 75 C Storage temperature range 40 to 75 C Relative humidity 0 to 90 non condensing Connections Screw terminals accept 12 to 22 AWG wire Enclosure NEMA...

Page 6: ...able from 0 to 99 999 seconds Open Collector Output Rating Isolated open collector sinking NPN 30 VDC 150 mA max Alarm Output Assign to rate for high or low alarm trip point Assign to total for total...

Page 7: ...and set the display module aside Unpacking Remove the meter from box Inspect the packaging and contents for damage Report damages if any to the carrier If any part is missing or the meter malfunction...

Page 8: ...t from external supply OUTPUT NPN open collector output positive OUTPUT NPN open collector output negative RESET Contact closure alarm acknowledge pull up to 3 VDC RESET Contact closure alarm acknowle...

Page 9: ...ions are made to two terminals labeled RESET Connect to a contact closure source such as a relay or a pushbutton as shown in Figure 7 Figure 7 Reset Connections Open Collector Output Connections Outpu...

Page 10: ...sors are disabled when a mechanical button is pressed and will automatically be re enabled after 60 seconds of inactivity The SafeTouch buttons are designed to filter normal levels of ambient interfer...

Page 11: ...nds to access the Advanced features of the meter Right Reset Button Press the Right arrow button to move to the next digit or decimal position during programming Up Display Button Press the Up arrow b...

Page 12: ...ogram menu sCalE Scale Enter the Scale menu Cal Calibrate Enter the Calibrate menu Inpt1 Input 1 Calibrate input 1 signal or program input 1 value DspL1 Display 1 Program display 1 value Inpt2 Input 2...

Page 13: ...w to select next digit and Up arrow to increment digit The digit being changed blinks Press the Enter button at any time to accept a setting or MENU button to exit without saving changes The decimal p...

Page 14: ...functions are exclusive of each other The meter uses the last function programmed Only one of these methods can be employed at a time The Scale and Calibrate functions can use up to 32 points default...

Page 15: ...complete the calibration or scaling of the meter The minimum span is 0 10 mA If the minimum span is not maintained the meter reverts to input 2 allowing the appropriate input signals to be applied Re...

Page 16: ...on choose man dsabl To reset total upon total alarm set point choose auto enter a time delay t dly and proceed to programming the set point see Alarm Output alrm on page 19 Press the Enter button at a...

Page 17: ...returns to its password protected condition Disabling Password Protection To disable the password protection access the Password menu and enter the correct password twice as shown below The meter is n...

Page 18: ...total Set Set Point Program set point Reset Reset Point Program reset point Pulse Pulse Output Program pulse output Scaler Count MAX HZ Frequency Program pulse output maximum frequency Funct Function...

Page 19: ...deadband is one display count If set and reset points are programmed the same output will reset one count below set point Total alarm trip point program total set point Alarm reset is triggered by tot...

Page 20: ...rent source instead of using input scaling This process will override previously programmed scaling points Apply a live signal using a known accurate signal source InP 1 32 and then enter the correspo...

Page 21: ...ging time and so the longer the display may take to find its final value The filter contains a noise filter bypass feature so that while small variations in the signal will be filtered out large abrup...

Page 22: ...he factory defaults Instructions to load factory defaults Enter the Advanced features menu Press and hold Reset button when INFO is shown Press Enter when RESET DFALTS prompt is shown Note If Enter is...

Page 23: ...exit Max Min display readings Display response is too slow Check filter setting to see if it can be lowered to LO or OFF If the display locks up or the meter does not respond at all Perform hard rese...

Page 24: ...on or increment digit Cycle through maximum minimum and mA display mode ENTER Accept selection value and move to next selection Acknowledge alarms Max Min Mode While in Run Mode pressing Up Arrow will...

Page 25: ...990 www predig com LIM6720_C SFT049 Ver 1 200 up 07 20 Contact Precision Digital Technical Support Call 800 610 5239 or 508 655 7300 Fax 508 655 8990 Email support predig com Sales Support Call 800 34...

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