Load Cell Amplifier, Indicator & Transmitter, IQ300

Load cell wall mount indicator
Model IQ300 
is a programmable wall-mount precision digital indicator for load cell and strain gauge applications.  The 4-line backlit sunlight readable graphic LCD display is quick and easy to set up with plain language menus and prompts.

With precision front end circuitry for high accuracy and stability, the ratiometric circuitry automatically compensates for temperature drift and excitation voltage variances due to cable loss.

5 or 10 VDC load cell excitation voltage is user selectable for use with both 4-wire and 6-wire load cells, powering up to 6 x 350Ω load cells.

Advanced features include auto-zero tracking; user input linearisation; max/min recording; programmable front pushbuttons; 3 programmable digital inputs; security menu lockout; motion indication; advanced digital filtering; automatic offset calibration; plus many more to provide an all-in-one precision load cell indicator.

RS232 and RS485 serial communications are standard with MODBUS™ RTU and MODBUS™ ASCII protocols.  A simple ASCII-out protocol is also provided for serial printing and communicating to large displays.

Model IQ300 includes 4 electromechanical relays, 16-bit analogue retransmission and a Real Time Clock.

  • High bright 6-digit 20mm LED display
  • Backlit 4-line graphic LCD for easy setup and calibration
  • 4 or 6 wire load cell / strain gauge input
  • Powers up to 6 x 350Ω load cells
  • 5V or 10VDC excitation voltage
  • High precision 22 bit ratiometric ADC front end circuitry
  • -199999 to +999999 display counts
  • Easy calibration using known weights or load cell data
  • 16 Bit Analog output (0/4-20mA or 0-10V)
  • RS232 communications (MODBUS™ RTU / ASCII and Infiniteq ASCII protocols)
  • RS485 communications (MODBUS™ RTU / ASCII and Infiniteq ASCII protocols)
  • 3 Programmable digital inputs (pull up or pull down field jumper selectable)
  • 3 Programmable front panel push buttons
  • 4 Form-C alarm relay setpoints
  • Cage-clamp wire connectors
  • 16 Point lineariser
  • Auto-zero tracking function
  • Automatic offset calibration
  • Tare function
  • Gross/Net function
  • Selectable and adjustable advanced digital filtering
  • Alarms, Motion indication and Net front panel status LED's
  • Max / Min recording
  • Security menu lockout
  • Built in menu help hints and prompts
  • Field upgradable firmware via the RS232 interface
  • 1 year warranty
General: Model IQ300
LED display 6-digit, 20mm (0.8”) 7 segment high brightness red LED
LCD display 128 x 64 graphic mono sunlight readable
Backlight Yellow / Green with on/off control
Display range -199999 to +999999
Decimal point   0 to 0.00000
Status LED's 8 LED's for SP1 to SP4, Zero, Net, Motion & Print
Digital Inputs 3 Programmable digital inputs
Built in hysteresis, filter and input over voltage protection
Maximum input voltage <30VDC
Input logic is field jumper selectable
(Pull up, sinking inputs) - 10kΩ internal resistor to 5V
(Pull down, sourcing inputs) - 10kΩ internal resistor to common
Active/Non-Active input trigger: <1.9V
Non-Active/Active input trigger: >2.3V
Keypad Full 4 x 3 alphanumeric
4 Dedicated function keys (Zero, Tare, Print, Gross/Net toggle)
3 Dual function keys (Display Toggle, Display Hold & Alarm latch reset)
Memory storage Non-volatile EEPROM, 100000 write cycles minimum
Warm up time 15 minutes
Power Requirements:
AC Supply 85-264VAC, 50/60Hz or 120-370VDC
Isolation: 3000VAC/1min
Low DC Supply 10-30VDC input
Reverse and over voltage protected
Isolation: >1000V/1min
High DC Supply 25-70VDC input
Reverse and over voltage protected
Isolation: >1000V/1min
Power Consumption <15W
Fuse (built in) 2A Slow Blow (Wickmann_3721200000)
RS components part number_226-6599
Operating temperature -10°C to 50°C (14°F to 122°F)
Storage temperature -40°C to 80°C (-40°F to 176°F)
Operating / storage humidity <85% RH non-condensing
Overall Dimensions 180 x 180 x 60mm (LxHxD) (7.09 x 7.09 x 2.36”)
(Height includes cable glands)
Mounting holes 159 x 94mm (6.26 x 3.70”)
Enclosure material ABS - Flame retardant (UL 94 V-0)
IP rating IP65 / NEMA 4 / UL Type 4
Connection type Cage clamp wire connectors
ADC Resolution 22 bit Delta-sigma
Input range -20mV to +35mV
Conversion rate 12 updates/second
Filter Moving average digital filter with programmable input step detection
Increment size 1, 2, 5, 10, 20, 50, 100, 200
Input Impedance >20 MΩ
CMRR >-110dB
Linearity <0.01% of full scale
Accuracy 0.05% of full scale
Calibration method From the load cell calibration certificate or using known weights
Load cell connection   4 or 6 wire connection + shield (sense included)
Load Cell Excitation:
Excitation Voltage Field jumper selectable 5V or 10V (sense included)
Excitation current Max. 125mA
Up to 4 x 350Ω or 8 x 1000Ω load cells
Cable compensation 4 wire Kelvin force sense feedback
Cable compensation resistance <= 10Ω
Analogue Output: (menu selectable)
Ranges 0-20mA
DAC Resolution 16 Bit
Update rate 12 updates/second
Current output compliance 500Ω maximum load
(Current is source, not sink)
Voltage output compliance 1kΩ minimum load
Open loop detection LCD display flashes “mA.Loop” error message
Linearity <0.02% of full scale
Accuracy 0.05% of full scale
ASCII In (Infiniteq Protocol)
ASCII Out (Infiniteq Protocol)
RS232 (standard) Baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
Data bits: 7 or 8 bits
Parity: Odd, Even or None
Stop bits: 1 or 2 stop bits
Non isolated
RS485 (optional) Baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
Data bits: 7 or 8 bits
Parity: Odd, Even or None
Stop bits: 1 or 2 stop bits
Internal 120Ω field jumper selectable termination resistor
Max 32 instruments per line
Setpoint Relays:
Electro-mechanical: (4 relays, standard)
Contact rating 2A@240VAC or 30VDC (resistive load)
Isolation to input circuitry >1000Vrms for 1 minute
Type FORM-C (change over contact, NO / NC)
Life expectancy >100K cycles min. at full load rating. External RC snubber extends relay life for operation with inductive loads
Solid-State (SSR): (optional, 1, 2, 3 or 4)
Contact rating 120mA@400VAC/DC
Isolation to input circuitry >1000Vrms for 1 minute
Type FORM-A (Normally open)
Real Time Clock:
Battery CR2032
Accuracy Better then 3 seconds per day (temperature dependent)
Order codes and options:

  IQ300 for 85-264VAC auxiliary supply
  -700   10-30VDC auxiliary supply
  -701   25-70VDC auxiliary supply
  -720   1 solid-state Form A relay
  -721   2 solid-state Form A relays
  -722   3 solid-state Form A relays
  -723   4 solid-state Form A relays

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IQ300 indicator functions
Wall mount load cell indicator functions
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