ADLINK USB-7230/7250 Isolation I/O Module Operation Manual

USB-7250: Each channel is differentially independent, without considering polarity, and can be directly connected to passive contacts (such as DIH and DIL at both ends of the switch) or active signals (DIH at the positive end and DIL at the negative end), greatly simplifying on-site wiring.

2. Change of State (COS) detection

The COS function can monitor the logic level transition (rising edge or falling edge) of a specified input channel and generate interrupt notifications to the upper computer. The module uses a 48MHz base clock for sampling internally, with a minimum detectable pulse width of 20.83ns (1/48MHz). When a channel with COS enabled undergoes a transition, the corresponding input data is latched into the COS latch register, which is automatically cleared after reading the register. Attention: Due to software response delay, it is recommended that the COS trigger frequency not exceed 1kHz, otherwise events may be lost.

3. Frequency/Event Counter

The counter is based on a 32-bit addition counter, which can count the number of rising or falling edges of the input signal (event counting mode), or measure the signal frequency (frequency mode). Frequency measurement principle: Count the number of 48MHz base clocks within a complete signal cycle (between adjacent rising or falling edges), and then convert them into frequency values. The frequency range is 0.1Hz~1MHz, and the measurement error increases with frequency - ≤ 0.5% for ≤ 50kHz, ≤ 1% for 50kHz~500kHz, and ≤ 2% for 500kHz~1MHz. For low-frequency signals, digital filters can be used to eliminate jitter.

4. Digital filtering

The filtering function is disabled by default for all DI and counter inputs. After activation, the minimum pulse width value (filtering level N, N=1~65535) needs to be set. The actual minimum pulse width is N × 20.83ns. Any pulse with a width less than this value will be ignored, effectively suppressing false triggering caused by contact jitter or electromagnetic interference. For example, if N=10, signals with pulse width<208.3ns will be filtered out.

5. Isolated digital output (USB-7230)

The output adopts an open drain structure, and an external load must be connected to VDD (5-35V). When the output is logic 1 (ON), the MOSFET conducts, and the load current flows through the load into the DO pin and then to IGND. Important reminder: If driving an inductive load (such as a relay coil), a freewheeling diode must be connected in parallel at both ends of the load (with the cathode connected to VDD and the anode connected to DO), otherwise the reverse induced voltage generated when turning off will break down the MOSFET. The module supports programming the initial output state when powered on, and can set the default state of each channel before the driver is loaded to avoid misoperation at the moment of power on.

6. Relay output (USB-7250)

The relay is a mechanical non latch type, and when the control position is 1, the excitation coil causes the contacts to close. C-type relays (CHO~3) provide normally closed contacts, suitable for applications that require failure protection (such as maintaining continuity during power outages); Type A (CH4-7) is only normally open. The lifespan of the relay can reach 1 million operations under resistive loads (50VDC/0.1A), and higher loads will shorten the lifespan. It also supports the initial power on state setting, but please note that the relay automatically returns to a low state when reset or USB is disconnected (COM and NC are conductive, type A is disconnected).

Installation, Connection, and Device Identification

1. Mechanical installation

The module size is 156.5 × 114 × 41.3mm, matched with a multifunctional bracket. Installation steps:

Desktop placement: Simply slide the module into the bracket until it clicks.

DIN rail: Use the included rail mounting kit (spring clip) to pre hang the module on the rail and press it in place.

Wall mounted: Fixed to the wall with countersunk screws through four mounting holes with a diameter of approximately 3.4mm on the back of the bracket.

2. USB connection and driver

Connect the standard locking USB cable (2 meters) to the computer USB 2.0 port. When first inserted, the system automatically recognizes and loads the firmware, and the LED indicator light changes from amber to green to indicate readiness. The module is only powered by USB (maximum 400mA). If connected to a USB hub or a port with insufficient power supply, it may cause recognition failure. In this case, a USB hub with an external power supply should be used.

3. Device ID setting

There is a rotary switch (0-7) on the back of the module for setting the device ID. When multiple modules of the same model are connected to the same computer, a unique ID must be assigned to each module, otherwise the software cannot distinguish them. This ID is independent of the USB port number, making it easy to map fixed devices.

Software Support and Testing Tools

ADLINK provides UD-DASK driver library (supporting 32/64 bit Windows 7/Vista and higher versions), as well as DAQPilot graphical SDK, which can lower the programming threshold. In addition, the free tool U-Test can directly operate all functions without writing code - it can be used to quickly verify hardware connections, monitor input status, manually control outputs, view counter readings, and perform FFT analysis. It is recommended to first use U-Test to confirm that the module is working properly during on-site debugging, and then proceed with development.