A customer needs to capture incoming satellite communication signals at a ground-based receiver. After analog demodulation and amplification, the signal is digitized by two 12-bit ADC chips clocked at a rate of 47.3 MHz. One ADC is used to scale a high-voltage input signal that has a mean value of 25.85 V. The second ADC chip is used to get better accuracy on the same signal, using a proprietary signal-scaling technique. The first ADC scales the full input voltage so that the second ADC only sees a small 50 mV signal around the mean 25.85 V. In this way, the combined system can achieve up to 22 bits of effective resolution. All ADC digital outputs are Transistor-Transistor-Logic (TTL).
The customer requires a high-speed digital input module with at least 24 input bits to capture data from both 12-bit ADCs. In order to achieve the combined 22 effective bits of resolution, it is paramount that all 24 bits be simultaneously sampled with the 47.3 MHz external clock. The signal must be captured in repetitive bursts that last 10 milliseconds each.
The GaGe CompuScope 3200-2M provides the ideal solution to the customer's requirement. With its 32 input bits and up to 100 MHz sampling capability, the CS3200 meets the main acquisition requirements. Furthermore, the CS3200 accepts TTL inputs and has 2 MB of on-board acquisition memory, which is more than sufficient for the 10 ms capture-time requirement. The external clock feature is standard on the CS3200 and the clock phase can be inverted, if necessary, so that its rising edge occurs when the digital data is stable.
Initially, the customer will capture data with the CS3200 using GaGeBit - Gage's standalone Windows-based digital input/output software, which provides a logic analyzer-like environment. GaGeBit allows the user to access all the functionality of the CS3200 without writing a single line of code. GaGeBit also provides digital data masking capability as well as several logical operators (NOT, OR, XOR, AND...), which can be used to separate data from the two ADCs. Using GaGeBit, the customer can immediately begin capturing and storing data on their prototype receiver system.
Down the line, the customer will develop their own integrated Windows-based application to control the final commercial receiver system. As a starting point for this application, they will use a sample program from GaGe's powerful C/C++ Software Development Kit. Using the off-the-shelf CS3200 and C/C++ SDK, the customer will have a powerful system completely customized to the satellite receiver requirement.
We encourage you to contact us and discuss your test & measurement application in more detail with our engineering team. GaGe can provide tailored custom data acquisition hardware and software solutions to meet specific application requirements.