3. A Tour of RAD-IO2 Hardware

The RAD-IO2 system supports several types of isolated I/O modules, each with distinct capabilities:

3.1. RAD-IO2-TC Thermocouple Module

• Banks/Channels: 8 independent banks, one K-Type thermocouple channel per bank.

• Isolation: Features channel-to-channel isolation without the need for mechanical relays, minimizing settling time and error. Each bank has its own Cold Junction Compensation (CJC) and A/D converter.

• Converter: 16-bit Delta Sigma Converter per bank.

• Thermocouple Type: K-Type only.

• Range & Accuracy:

  • Range: -270°C to 1260°C

  • Typical Accuracy: Better than ±1°C (each channel is individually calibrated by Intrepid)

  • Resolution: 0.2°C

  • Accuracy: ±2°C (specification)

• Noise Rejection: >105 dB Common Mode Rejection at 60 Hz and 50 Hz.

• Note: K-Type Thermocouples are not included; purchase separately (e.g., from Omega.com).

3.2. RAD-IO2-AIN Analog Input Module

• Banks/Channels: 8 independent banks, each with a 16-bit Delta Sigma A/D converter. Functions as 8 independent, “floating” voltmeters.

• Ranges (Selectable):

  • Low Range: ± 250 mV, ± 1000 mV, ± 5000 mV.

  • High Range: ± 10V, ± 20V, ± 45V.

  • Caution: Only one range (Low or High) can be used per bank at a time. DO NOT exceed the maximum voltage for the selected range to prevent unit damage.

• Resolution: 16-bit. Delta-sigma (ΔΣ) technology provides reduced “jitter” when using slower conversion speeds due to internal sample averaging.

• Sampling Rate:

  • Maximum aggregate across all daisy-chained modules: 1000 samples per second (sps).

  • Maximum per channel: 100 sps.

  • Example: 24 channels yield approximately 41 sps (1000/24). One channel yields 100 sps.

• Use Case: Suitable for most static or semi-static measurements; too slow for electrical transients, microphones, or accelerometers.

3.3. RAD-IO2-AOUT- Analog Output Module

• Banks/Outputs: 8 isolated output banks. Total of 24 analog outputs (three 0-5V outputs per bank, with one common ground line per bank).

• Converter: 16-bit Digital-to-Analog Converter (DAC).

• Resolution: 76.3 µV per bit.

• Current Output: 5mA maximum output current per channel (limited by the drive chip).

• Power: Approximate current draw if all channels output maximum current: 370mA.

• Update Rate: Subject to the same 100 samples per second limitation as the AIN module when updating the analog signal output.

3.4. RAD-IO2-PWRRLY Power Relay module

• Relays: 8 isolated Form C relays. Each has normally open (NO) and normally closed (NC) connections. The two common connections (pin 2 and pin 3) are internally tied together.

• Switching Capacity:

  • Current: 5A (for DC up to 220VDC) and 5A (for 250VAC).

  • Power: 60W / 62.5VA.

  • Max DC Load Breaking Capacity specified.

• Contact Specifications:

  • Material: AgNi (Silver and Nickel), gold plated.

  • Initial Contact Resistance: <50mΩ at 10mA/30mV.

• Durability:

  • High mechanical shock resistance (up to 50g functional).

  • Electrical Endurance:

    • (≤30mV/≤10mA): min. 2.5 million operations.

    • Cable load open end: min. 2 million operations.

    • Resistive, 220 VDC / 0.27A - 60W: min. 500k operations.

3.5. RAD-IO2-DIO Digital In/Out module

• Structure: 8 isolated banks with one common ground per bank.

  • First 4 banks are inputs (12 total inputs).

  • Second 4 banks are outputs (8 total outputs).

  • All banks are mutually isolated.

Digital Inputs (4 Banks / 12 Total)

• Input Type: Three 0-40V, 12-bit Analog-to-Digital Converter (ADC) inputs per bank.

• Configurable Modes (reconfigurable during operation):

  1. 0-40 VDC Analog Input: Reports an analog value.

  2. Digital Input: Reports a digital (0 or 1) value based on a programmable 160mV step threshold.

  3. PWM Input: Reports a digital (0 or 1) value based on a programmable 160mV step voltage threshold.

  4. Period Measurement

  5. Frequency Measurement

Digital Outputs (4 Banks / 8 Total)

• Output Type: Each of the 4 isolated output banks has two digital outputs.

• Configuration: Can be configured as separate digital channels (Half Bridge) or combined as a Full H-Bridge output. Four pairs total (8 channels).

• Power: Each output can pass 5.5V to 40V at 6A (user-supplied). Uses one BTN8962TA chip per output.

• Programmable Modes:

  • Simple Digital Output

  • One Shot Output

  • PWM and frequency programmable output

  • Half Bridge Mode (when channels are separate)

  

  • FULL BRIDGE MODE (when channels are joined)