Wireless Telemetry Potentiometer Acquisition Module (T24-RA)

The T24-RA radio potentiometer acquisition module is a high performance wireless device designed for the collection and processing of resistance related measurements. The module measures resistance and periodically transmits it. Between transmissions the device is optionally placed in a power saving sleep mode to conserve batteries.

Miniature in size, the string pot device transmits on license-free 2.4Ghz, avoiding local radio interference to ensure data integrity and security.

Data is provided in real time at variable speeds with a direct line of sight range of 100 or 200 meters which can be extended with the use of high gain antenna’s and repeaters. View our range of antennas here.

The module’s transmit to a range of receivers including handheld indicators, digital displays, analogue and serial outputs, PC display and wireless printer and has various powering options.

Also available in a selection of IP rated enclosures. See T24-ACM-RA, T24-ACMi-RA and T24-ACMm-RA.

 Module transmits and receives giving:

1. Full error detection and correction
2. Ability to switch to low power modes
3. Calibration & configuration via radio telemetry
4. Ability to be switched from sleep to operating mode via radio
5. Calibration stored within the module
6. Remote battery check
 

Product order options

These are the following industries and applications in which this product has been used:

• Agriculture - Vessel Level Control & Flow Sensing

Q: Can I use a rotary input?

A: The T24-RA is designed to work with potentiometer inputs that pass from 0-100%. To avoid the T24-RA providing numbers that are outside the calibrated output the module has a rotary limit. This is the value at which the input is expected to move between the maximum and minimum values.

Q: Can I just measure a resistance?

A: The T24-RA is a potentiometer input which means it can not measure resistance directly yet if wired into a potential divider circuit, with a known resistor value, the change in resistance can be measured.

Q: How do I calibrate the device?

A: The module has a 9 point linearization and calibration feature which allows users to calibrate the percentage output into whatever units are required. For example, calibrating a linear potentiometer would be performed by entering the distances that the plunger you want to measure moves and calibrating at 9 points over that range.

Q: What output does the device provide?

A: The T24-RA is factory fitted and calibrated to provide an output between 0-100% as the input value varies between the negative and positive excitation.

Q: What software is provided with the T24 devices?

A: All devices are supported by the T24 Tool Kit which allows users to
configure all devices from the T24 range as well as view and log data from
acquisition modules in range. The software can also be downloaded directly
from our website.
 

Q: How many devices can operate on one radio channel?

A: Many devices can operate on the same radio channel depending on the sample rate of the acquisition modules present in the system. There are 16 channels available with each one capable of supporting up to 200 data packets per second.

Q: Can PC software gather data from many devices?

A: Yes, Mantracourt provides freeware for logging up to 24 inputs to one base station, in addition the open COM driver can be used to gather data through customers own PC software to applications in Visual Basic which in turn has been used to integrate the T24 system with Lab View.

Q: What limits the RF range of the devices?

A: Any metal surface will reflect 2.4 GHz radio waves, therefore in a sealed metal box, no RF will escape. However by providing a suitable RF window the signals will propagate out.

Q: What Frequency does the system operate on?

A: Licence free world wide 2.4GHz, although this frequency is used by other equipment the T24 range has been tested with Bluetooth, Zigbee & WiFi devices with out conflicts.

Q: Is it possible to use repeaters within T24 network?

A: The T24-AR Active repeater which can be added to the system can propagate a signal around corners and obstacles. This unit can also double the effective range.

Q: Is the system point to point?

A: Yes, however the modules may also operate in many to one (such as multiple data acquisition modules communicating with a base station) and one to many (such as a data acquisition module supplying data to multiple handhelds and displays).

Q: What sensors would these inputs cover?

A: Any sensor that provides a voltage, current or ratio metric interface can be connected to an acquisition module, including load cells, inclinometers, accelerometers, displacement LVDT, pressure, potentiometer, pulse, temperature, humidity, ph, shock.

Q: What is the communication protocol?

A: Proprietary protocol based on a 804.15.4 chip. This allows the T24 range to co-exist with Bluetooth, Zigbee & WiFi devices with out conflicts.

Q: What are the sampling rates of the acquisition modules?

A: The T24 standard acquisition modules (SA, IA, VA, RA, TA, PA) sample from 0-200 updates/sec. The T24-SA fast acquisition modules are fixed at 2,000 updates/sec.

Q: What is the resolution of the acquisition modules?

A: The noise free resolution for a sample time of 10 milli-seconds or less is 15.5 bits for the T24 SA, 12.5 bits for the T24-VA, 14 bits for the VA and 12.25 bits for the T24IA.

The T24-PA’s accuracy % input error @ 1 Hz is 0.15% and for the T24 RA the accuracy is 0.01% of the full scale.

With increased sample times resolution can be increased up to 18.75 bits for the T24-SA.
 

Q: What is the supply voltage for the acquisition modules?

A: 3V for the acquisition modules and handheld displays. Other modules in the range take 9-36 V.

Q: How are the modules powered?

A: Two standard AA batteries or the T24-BC1 Battery Charger, which provides a re-chargeable power supply using a Li-ion Cell. Find out the battery life of your system using our Battery Calculator.

Q: Can power be provided to a sensor?

A: Yes, all acquisition modules feature a 5V supply which is a excitation voltage (with exception of T24-RA which has 2.5V supply).

Q: How is the strain gauge acquisition module calibrated?

A: The modules are factory calibrated to 2.5 mV/V which can be custom calibrated and linearised over up to 9 points by using the T24 Toolkit. The T24-SAf has fixed factory calibration and cannot be linearised.

Q: What is the difference between the ‘i’ and ‘e’ versions of the acquisition units?

A: The ‘i’ modules all feature an on chip integrated antenna. The ‘e’ modules are fitted with a miniature UFL connector which can be used with any of the antenna options available; the T24-ANTA (PCB antenna) or T24-ANTB (fixed 90 degree Whip antenna) or T24-ANTC (flexible whip antenna).

Q: How many acquisition modules can be acquired by the base stations?

A: Each base station can use one of 16 channels. From one of those channels a base station can collect data simultaneously from any number acquisition modules depending upon the frequency of readings being provided by the acquisition module.

Q: What are the input ranges of the T24 acquisition modules?

A: T24-SA 2.5mV/V calibrated strain gauge based measurement; T24-VA 0-10V, T24-IA 4-20mA, T24-TA pt100 sensor input, T24-RA potentiometer 500 to 100000 Ohms and T24-PA 0.5Hz to 3kHz.