APCS the Signal Conditioning Specialists


USC Applications

Although the new module wizard can program the USC701 to become thousands of different signal conditioning modules, USC applications have been developed as a means of extending the functionality of the USC701. The available applications can be used as they are or as a training tool to develop your own programs using the equation editor.

For a small charge APCS will develop new specific applications for customers. If you do not wish your application to be listed on this site you can develop it yourself or pay a higher development fee.

USC Application (uap)

Incomplete Application List

There is 16 years of published application history that is progressively being added to the site. If your application is missing from the list please email the UAP number to andrew@apcs.net.au and I will endeavour to add it quickly and email you back a copy.


USC Applications List


UAP0001 RelativeHumidityMonitor

USC Application (uap) Relative Humidity Monitor (from Wet + Dry Temperatures)

The USC is connected to a Pt100 probe on CH1, dry bulb temperature and Pt100 probe on CH2, wet bulb temperature.

RH is equal to the ratio of actual vapour pressure of air (e) to the maximum possible vapour pressure at that temperature, ie the saturation vapour pressure (es).


UAP0002 Dew Point Monitor (from RH + Temperature)

USC Application (uap) Dew Point Monitor (from RH + Temperature)

The Dew Point Temperature is the temperature of an object at which condensation will start to collect. At Dew Point temperature, the amount of water vapour present in the air is equal to the maximum amount of vapour that air can hold at that specific temperature.

The USC is connected to a Pt100 probe on CH1 and a humidity transmitter on CH2.


UAP0003 Sewer Discharge Pump Disable by Rainfall

USC Application (uap) Sewer Discharge Pump Disable by Rainfall

Disable a sewer discharge pump from operating during wet weather.

After the 1mm of rainfall the power supply to the pump is isolated for at least one hour after the cessation of rain. In some areas the pump isolation time will need to be increased as necessary in 1-hour blocks.


UAP0004 Volume-Cylindrical Tank on Side (height)

USC Application (uap) Volume-Cylindrical Tank on Side (height)

Calculates the volume of liquid in a cylindrical tank on side. Note that the area calculation will fail if the height measuring device (h) returns a height greater than two times the radius. If this is likely to happen extra code could be added to the equation list of a sensor fail alarm could be setup on one of the relay outputs.


UAP0005 PWM Relay Control plus External Ratio Adju

USC Application (uap) PWM Relay Control plus External Ratio Adjust

CH1 is the process variable being controlled and is scaled for (4 to 20mA) input and is equal to (0 to 1 Process) output.

CH2 is connected to a panel mounted potentiometer and is used to change the gain in the PWM output on RLY1. CH2 is scaled for (0 to 5k Ohm) input is equal to (0..1 Ratio) output.


UAP0006 Linearise a Portion of the Full Range

USC Application (uap) Linearise a Portion of the Full Range

Tables are used by the USC to linearise or correct for errors in an input signal. Each table has 101 points at exact even intervals of the input range. This type of correction works well if the points of non-linearity are over the whole input range. However in this example there is a non-linearity over the first 10% of the input and the rest of the range is linear. This example achieves 100 points of correction over the first 10% of the input by using two tables.


UAP0007 Deviation Alarm with sensing of signal(s)

USC Application (uap) Deviation Alarm with sensing of signal(s) drop out
  • If the input to CH1 is below dropout then RY1 is OFF.
  • If the input to CH2 is below dropout then RY2 is OFF.
  • If CH1 and CH2 are within the deviation level then RY1 and RY2 are ON, this is the no fault condition.

If inputs are above dropout and are more than the deviation then the higher of the two inputs is OFF.


UAP0009 Ramp Function with up, down, reset and rat

USC Application (uap) AC Load Monitoring
  1. While P1 contact is closed, the output ramps from the minimum value to max value in 100msec steps, ("Equation Evaluation" "Timer" enabled at 0.1sec).
  2. While P2 contact is closed, the output ramps down.
  3. When the master reset (MR) button is closed, the output jumps to the min value.

The default ramping time is 5 seconds (ie. 50 steps).


UAP0010 Reverse Acting Relay with Long Off Delay

USC Application (uap) Reverse Acting Relay with Long Off Delay Example

Because the on and off delays on the relays only go up to 2330 seconds this example uses an equation to obtain a one hour delay.


UAP0011 Wind Speed and Direction

USC Application (uap) Wind Speed and Direction

If using a standard AM702 please use the updated application UAP1073

This program is used in conjunction with the "AM704-0101 Wind Speed and Direction" access module. With this special version of the access module:-

  • Relay 1 can be set to trip at a selected wind speed, when the wind direction is between two selected levels.
  • Relay 2 can be set to trip at a selected wind speed.
  • On and off delays can be set.
  • The analogue output type and levels can be set representing either wind speed or direction

UAP0012 Suction Protector plus Oil Seal Monitor

USC Application (uap) Suction Protector plus Oil Seal Monitor

This example is used in a pumping station to monitor a water pump.

It uses fail safe logic (relay closed when good) and is part of an overall control system.


UAP0013 Ramp Up Down Movement Counter

USC Application (uap) Ramp Up Down Movement Counter

This application is used to detect 0.1Vdc changes in a 0-10Vdc signal. Two relays will transmit any positive or negative 0.1Vdc changes allowing an external counter to count overall movement. This movement will not be more than one 0.1Vdc change per second. A final input will be used to stop change count of the 0-10Vdc signal (drill head) whilst it is being raised (a new drill section is being inserted or removed). Faster times can be achieved by changing the timer value, timer values below 30ms will not give consistent results due to the speed of the relay contacts.


UAP0014 Building Blind Control based on Wind Speed

USC Application (uap) Building Blind Control based on Wind Speed

User variables in this application can be trimmed with the AM702-02 Operating Description

The USC is programmed to produce two alarm relays that will trigger the operation of motors on a external blind system. The high wind alarm will change the angle of the blind. The very high alarm will close the blind.


UAP0015 Ramp Up/Down To Control Pressure

USC Application (uap) Ramp Up/Down To Control Pressure
UAP0015-RampUpDown ControlPressurr-4.zip

In this application the USC is acting as a simple controller. Input 1 is connected to a 4 to 20mA signal representing 0 to 1000 kPa pressure from a transducer. The USC will regulate a 0 to 6Vdc output on terminals 11 and 12 to go to the pressure-controlling device.


UAP0016 USC701 Measurements with Load-Cell/Strain-

USC Application (uap) USC701 Measurements with Load-Cell/Strain-Gauge

As the USC701 is truly a universal signal conditioner problems with setting up some sensors may occur due to assumptions made by the engineer at the time of user calibration.

This article is intended to show the potential problems and the methods to overcome them.


UAP0017 Detect extra material in Stamping Machine

USC Application (uap) Detect extra material in Stamping Machine

Two or four strain gauge modules are mounted on the press face of a stamping machine to measure the stamping pressure. When in calibrate mode the machine is run under normal conditions, stamping one thickness of material, the peak pressure imposed on the machine is measured and stored.

When in run mode the peak pressure is again measured. This pressure is compared with the stored level and when 10% higher than the stored level (occurs when more than one thickness of material is in the press) the machine will shut down.


UAP0018, Speed Control of 4 Gear Motors

USC Application (uap) Speed Control of 4 Gear Motors

A master 4 to 20mA signal is fed into a USC to set the required speed rate from 0 to 100%

The USC will measure the speed of the motor via a proximity sensor on the output shaft. The speed range on the output shaft is 0 to 5Hz.

The difference between the master speed setting and the actual speed is calculated and saved in Mem6 as a percent deviation signal (Dev%).


UAP0019 Alarm - Inverted Can Detector

USC Application (uap) Alarm - Inverted Can Detector

The state of pulse input 1 P1, and pulse input 2 P2, are continually monitored. If both inputs are high at the same time then a inverted can has been detected.

When a inverted can has been detected the value 100 is saved in memory 4 M4 causing relay 1 latch on.

Relay 1 will remain on until the reset button is pressed causing more than 5 volts input to CH1 which then saves 0 in M4 causing relay 1 to release.


UAP0020 Analogue Sensor Signal to RTD Converter

USC Application (uap) Analogue Sensor Signal to RTD Converter

he USC701 is combined with the RTD/Resistance Simulator to convert an analogue signal (or sensor input) to a resistance output. The example below shows the conversion of a Thermocouple input to an equivalent RTD output.

The USC701 converts the input signal (with any necessary linearisation or cold junction compensation) to a pulse width modulated signal that adjusts the SPL0627 resistance output to the required output.

The pulse width modulated control signal input to the SPL627 has a defined non-linear relationship with the resistance output. The USC701 performs all the necessary calculations to ensure the correct output is generated.


UAP0021 Universal Tilt Alarm using X and Y Sensors

USC Application (uap) Universal Tilt Alarm using X and Y Sensors

A dual axis tilt sensor is connected to the USC. The USC converts the tilt signals from the X-axis (pitch) and Y-axis (roll) to a resultant angle. This resultant angle can be used to set the relay contact trip points and can be sent as an analogue output for metering and control. For tilt exceeding set value, the contact can be used to stop the process.


UAP0022 Low Chlorine in Drum Alarm

USC Application (uap) Low Chlorine in Drum Alarm
  1. A load cell is used to weigh a drum of chlorine. The signal from the load cell is conditioned by the USC701 to produce a 4-20mA output and a relay alarm.
  2. The 4-20mA output will represent 0 to 920kg of chlorine liquid within a drum.
  3. P2 is pressed after a full chlorine drum is placed on weigh platform the combined weight of a full drum of chlorine is stored in constant "b". As this is a non-volatile save changes must be greater than the jitter value before writing into the eeprom to prevent continuously writing data into the internal eeprom.
  4. With P2 in the un-pressed sate the value read from the weigh platform is subtracted from the tare weight (constant b ) and added to 920 (constant a weight of chlorine in a full drum) and saved in memory 5. The value in memory 5 will be 920kg when the drum is full. The value in memory 5 will reduce to zero as the chlorine empties out of the drum.
  5. Relay 1 will switch when the chlorine is reduced to 20kg.
  6. Relay 2 could optionally be used to switch on the actual weight of the drum plus chlorine as a safety measure in the event that the tare button was pressed when the drum was not full.

UAP0023 acA 0.25-50Hz bandwidth 2S response low ri

USC Application (uap) AC current 0.25-50Hz bandwidth, 2 sec. response, low ripple

The USC701 has been programmed to convert 0-400mV r.m.s. input to 4-20mA. The average of the AC signal is updated every 2 seconds with low ripple in the output.

When "USC Config 105" was released the input channel now automatically sets to this operating mode if a sample time above 500mS is selected. The new sample times available are 1000mS, 2000mS and 4000mS, when these times are selected on ac input ranges the A-D sample rate is reduced to 900Hz instead of the standard rate.


UAP0024 One Pole Adjustable Filter (0.435 update)

USC Application (uap) One Pole Adjustable Filter (0.435 update)

This application is similar to UAP1104 except the equation update time is always 0.435 seconds. The filter provides moving average of (k +1) samples.


UAP0025 PID Control plus Ziegler Nichols tuning Me

USC Application (uap) PID Control plus Ziegler Nichols tuning Method

This application contains a standard PID algorithm that can be used to control any number of devices. The USC can be programmed to accept an input signal, condition it, compare it to a set point signal and produce a corrective output signal.


UAP0026 Input follow + Offset + PID + Auto/Manual

USC Application (uap) Input follow + Offset + PID + Auto/Manual hot keys

This application is a backup PID controller and operates in two modes of operation.

Auto Mode :The ACCESS module displays pressure measured byCH1 in auto mode.
The mA signal going to valve 1 is measured (CH2) and retransmitted to value 2 with an offset value added.
The second input measures a pressure; if the pressure goes above a set point a backup PID function will further reduce the output valve angle to control output.

Manual Mode :The ACCESS module displays 'Valve2' angle as a percentage in manual mode.
'Valve2' angle can be adjusted using AM702 hot keys.


UAP0027 Conveyor App Utilising HOT keys for Tare a

USC Application (uap) Conveyor App Utilising HOT keys for Tare and Known Weight Cal

In this application the USC701 converts the loadcell information to a 4-20mA analogue signal.

Periodic loadcell calibration is achieved through an automated process using hot keys on the access module.


UAP0028 Efficiency Monitor

USC Application (uap) Efficiency Monitor
UAP0028-Efficiency Monitor-3.zip

A 4-0mA signal is fed into a USC that measures this input in 0 to 100 % efficiency Engineering Units.

The USC saves this input value every one-second and then every minute the last 60 readings are averaged and sent to the 4-20mA output.

The USC will continue to average the measurements until a reset signal is received on the P2 input. This reset signal resets all counters to zero and the averaging restarts from this point.


UAP0029 Dosing Alarm Monitor For 2 Pumps

USC Application (uap) Dosing Alarm Monitor For 2 Pumps
  1. When there is no power applied to pump 1 [2] the contact input to CH1 pin 13 [CH2 pin 20] is off (0Vdc). This will disable the operation of the dosing monitor input P1 [P2] and cause the alarm relay RLY1 [RLY2] to be switched off.
  2. When dosing pump 1 [2] is running contact input to CH1 pin 13 [CH2 pin 20] is closed (8Vdc). This will enable the operation of the dosing monitor input P1 [P2].
  3. If P1 [P2] is low (measured as active high), value 1 (equation constant b) is saved in memory M4 [M5], this will cause RLY1 [RLY2] to trip after a 30 sec delay set the relay configuration.
  4. If P1 [P2] is high, value 0 (equation constant a) is saved in memory M4 [M5], this will cause RLY1 [RLY2] to switch off or stay off and reset the trip delay.

UAP0031 Linear Integrator

USC Application (uap) Linear Integrator
UAP0031-Linear Integrator-3.zip

Convert the measurement process signal into a pulse train where the output frequency is higher. The user needs to enter the value of maximum pulse/minute (ppm).


UAP0030 Cat Engine PWM Throttle Ramp Control with

USC Application (uap) Cat Engine PWM Throttle Ramp Control with Limits
  1. The USC701 will produce a PWM 500Hz output to suit Caterpillar electronic engines. The PWM duty cycle is limited by the standard wizard signal limiting controls to 5% minimum (minimum speed) and 95% maximum (maximum speed).
  2. The PWM output will follow the value stores in memory 4 of the USC701.
  3. The speed is controlled via a 10K potentiometer connected into channel 1 where 0Vdc represents minimum and 8Vdc represents maximum speed.
  4. An enable contact input (Pulse 1) is used to ensure minimum throttle when the motor is started.