fishywisky

This a cable that was ordered on https://fr.rs-online.com/web/p/cables-coaxiaux/7839644?srsltid=AfmBOooQtuDgQOfWAG9ac5nyBZN7bDeP1XEpyXZ23D92NFiU_-NIuusP. Informations : " RG174 Coaxial Antenna Cable This low-power radio solution offers users antenna cables to connect SMA connectors to wireless applications. The 150 mm RG174 is an antenna cable with a straight male SMA plug on one end and a panel-mount female SMA plug on the other. What is a Coaxial Cable? A coaxial cable is a specific type of cable made of copper combined with other metallic shielding materials and components to block signal interference. It includes a physical channel for carrying the surrounding signal, usually accompanied by an insulating layer. How Do Coaxial Cables Work? Coaxial cables work through concentric layers of electrical conductors and insulating material. This structure ensures that a signal is contained within the cable and prevents any electrical noise from disturbing the signal. Typical Applications Signal transmission for televisions and antenna connections Signal transmission for surveillance camera images Broadband signal transmission Connecting satellite antenna equipment to homes and businesses Interconnecting telecommunications and data equipment in industrial settings Facilitates the transmission of radio frequency signals Excellent for industrial purposes as well as portable devices Commonly used for low and high-power radio frequency (RF) connections Examples include radio tower antenna connections, CB and cell phone antenna connections, and microwave transmitter and receiver applications Features and Benefits RoHS compliant Weight: 10 g Nominal impedance: 50 Ω Straight male SMA connector and panel-mount female SMA connector LPRS 150 mm RG174 Antenna Cable This LPRS 150 mm RG174 antenna cable is equipped with a male SMA plug on connector A and a female SMA plug on connector B. The total length is 167 mm and it offers a characteristic impedance of 50 Ω. External Antennas " Did you modify the SMA cable? Yes, I extended the ground and signal wires (see picture). Have you tested a standard BNC 50 Ohm cable with the USB-1808X output? Yes, but I still noticed the offset. What’s strange is that even when I unplug the SMA the cable, wait, restart my computer, run an example code from the MCCULW library (a_out_scan.py), I still see this small offset. a_out_scan.py

Hello, I've been working with the USB 1808X DAQ, outputting an analog signal on AOUT1. Everything is fine until I output my siangal in the pluged SMA cable, then my signal develops an unwanted offset. I waited a day and redid the test with flying cables, and I got a perfect signal with a 0V offset. However, when I plug in the SMA cable again, BOOM, the offset comes back. The cable doesn't short circuit the analog output to ground. No voltage is applied to the non-DAQ end of the cable. I tried connecting the pins to the ground of the DAQ and the ground of a generator. I tried to unplug and replug the DAQ but the offset is still there just after the init led stops blinking. My computer in linked to the ground via it's charing cable. Thank you in advance.

Hello Fausto, Thank you alot for your reply.

Hello, I am an intern at my company, and my task is to create a testing workbench for our main product. For this purpose, I was provided with an MCC DAQ USB 1808 X. However, the number of available channels was insufficient, so they acquired a USB 1608GX-2OA, allowing me to use 16 pins in single-ended mode. A small problem has arisen: I need to sample my incoming signal at roughly 200KS/s. To acquire these signals, I use the MCCULW function "ul.a_in_scan()" where I specify my 16 channels after configuring them in single-ended mode. To my surprise, I encountered the error: "Active DAQ device: USB-1608GX-2AO (219D2A1) 'Starting scan on analog input ports 0 to 13 ... Error 24: Invalid sampling rate." with a samling rate at 177000. Here is my question: Am I misunderstanding the sampling rate capabilities? Is the 500KS/s rate divided by the number of channels I am using? How can I bypass this issue, if possible? Thank you for your assistance.

Hello, I started an internship and I must write a script in Python that scans multiple pins on my board (MCC DAQ USB 1808 - X) and saves their values into CSV files for testing. To optimize my time, I wanted to use the a_in_scan() function to scan multiple pins in one go. However, the values that I get are really bad and incorrect. I have the impression that the sampling rate is not what I intended (my signals are two PWM signals of 29.5 kHz and a chirp from 1-2500 Hz). I manage to get accurate values when I perform solo scans. Here is the code: """ from __future__ import absolute_import, division, print_function import csv from builtins import * # @UnusedWildImport from ctypes import POINTER, c_double, c_ulong, c_ushort, cast from mcculw import enums, ul from mcculw.device_info import DaqDeviceInfo def run_example( duration_RT, sampling_rate_RT, csv_filenames, PIN_RT_IN_start, PIN_RT_IN_end ): board_num = 0 points_per_scan = int(sampling_rate_RT * duration_RT) num_pins = PIN_RT_IN_end - PIN_RT_IN_start + 1 total_count = points_per_scan * num_pins if len(csv_filenames) != num_pins: raise ValueError("Number of CSV filenames must match the number of pins.") try: daq_dev_info = DaqDeviceInfo(board_num) if not daq_dev_info.supports_analog_input: raise Exception("Error: The DAQ device does not support analog input") print( "\nActive DAQ device: ", daq_dev_info.product_name, " (", daq_dev_info.unique_id, ")\n", sep="", ) ai_info = daq_dev_info.get_ai_info() ai_range = ai_info.supported_ranges[0] scan_options = enums.ScanOptions.FOREGROUND if enums.ScanOptions.SCALEDATA in ai_info.supported_scan_options: scan_options |= enums.ScanOptions.SCALEDATA ul.a_chan_input_mode( board_num, PIN_RT_IN_start, enums.AnalogInputMode.SINGLE_ENDED ) if enums.ScanOptions.SCALEDATA in scan_options: memhandle = ul.scaled_win_buf_alloc(total_count) ctypes_array = cast(memhandle, POINTER(c_double)) elif ai_info.resolution <= 16: memhandle = ul.win_buf_alloc(total_count) ctypes_array = cast(memhandle, POINTER(c_ushort)) else: memhandle = ul.win_buf_alloc_32(total_count) ctypes_array = cast(memhandle, POINTER(c_ulong)) if not memhandle: raise Exception("Error: Failed to allocate memory") ul.a_in_scan( board_num, PIN_RT_IN_start, PIN_RT_IN_end, total_count, sampling_rate_RT, ai_range, memhandle, scan_options, ) print("Scan completed successfully on analog input ports") data_per_pin = [[] for _ in range(num_pins)] x = [] for index in range(points_per_scan): t = index / sampling_rate_RT x.append(t) for pin in range(num_pins): if enums.ScanOptions.SCALEDATA in scan_options: eng_value = ctypes_array[index * num_pins + pin] else: eng_value = ul.to_eng_units( board_num, ai_range, ctypes_array[index * num_pins + pin] ) data_per_pin[pin].append(eng_value) for pin in range(num_pins): csv_file_path = csv_filenames[pin] with open(csv_file_path, mode="w", newline="") as file: writer = csv.writer(file) for i in range(len(x)): writer.writerow([x[i], data_per_pin[pin][i]]) ul.win_buf_free(memhandle) except Exception as e: print("\n", e) finally: ul.release_daq_device(board_num) if __name__ == "__main__": csv_filenames = ["TP901.csv", "R804.csv", "TP900.csv"] run_example(10, 200000, csv_filenames, 0, 2) """