Series Overview and Selection Positioning
In the field of industrial automation and testing measurement, isolated digital I/O cards are a key bridge connecting computers with on-site sensors, actuators, relays, and other equipment. The 723X series product line launched by ADLINK Technology has long held a stable market position due to its high isolation voltage, multi-channel configuration, and flexible interface form. This series covers four core models:
PCI-7230/cPCI-7230/LPCI-7230/LPCIe-7230: Provides 16 isolated digital inputs and 16 isolated digital outputs, suitable for general scenarios that require bidirectional isolated signal interaction.
PCI-7233: Designed specifically for pure input applications, it provides 32 isolated digital inputs and integrates a unique COS (Change of State) state change detection function, suitable for monitoring a large number of switch signals.
PCI-7234/7234P: Pure output model, providing 32 isolated digital outputs, of which 7234 is sink current type and 7234P is source current type, which can be flexibly selected according to external load requirements.
The interface forms cover traditional 32-bit 5V PCI bus (PCI-7230/7233/7234), 3U CompactPCI (cPCI-7230), low-voltage PCI (LPCI-7230, supporting 3.3V or 5V), and PCI Express x1 (LPCIe-7230), ensuring compatibility with various industrial control hosts. All models use ASIC PCI controllers, fully compliant with the PCI local bus specification Rev 2.1, and have plug and play (PnP) features. The BIOS automatically assigns base addresses and interrupt numbers, without the need for manual jumper settings, greatly reducing the difficulty of system integration.
Comparison and Selection Points of Core Electrical Specifications
2.1 Isolation input characteristics (applicable to the entire 7230/7233 series)
Number of channels: The 7230 series has 16 channels, while the 7233 series has 32 channels.
Input voltage range: DC 0~24V, logic low level 0~1.5V, logic high level 5~24V.
Input resistance: 1.2k Ω @ 0.5W, ensuring controllable power consumption at higher voltages.
Isolation voltage: PCI-7230 and cPCI-7230 provide 5000Vrms (between channels and between channels and computers), while LPCI-7230 and LPCIe-7230 provide 2500Vrms (excluding cables). The selection should be based on the on-site insulation withstand voltage level.
Maximum throughput rate: 10kHz, suitable for low-frequency switch signal acquisition, such as button, limit switch, relay status, etc.
2.2 Isolation output characteristics (applicable to 7230/7234 series)
Output type: Darlington transistor open collector (7230/7234 for sink current, 7234P for source current).
Output voltage: External power supply minimum 5VDC, maximum 35Vdc.
Driving ability: maximum single channel 500mA@100 %Duty cycle (for any one of the 8 transistors conducting); When multiple channels are conducting simultaneously, they need to be downgraded for use. For example, when PCI-7234 conducts all 32 channels simultaneously at a 10% duty cycle, the total current can reach 370mA (fill current), while the 7234P has a total source current of 260mA at a 10% duty cycle. In the design, the total power consumption needs to be calculated based on the load type (relay, LED, small solenoid valve) to avoid exceeding the limit of single channel or total current.
Isolation voltage: Same input side, 5000Vrms (7234/7234P).
2.3 Power consumption and environmental parameters
PCI-7230:+ 5V@150mA (Typical);
cPCI-7230:+ 5V@270mA ;
LPCI-7230:+ 5V@150mA ;
LPCIe-7230:+ 3.3V@279mA + + 12V@133mA ;
PCI-7233:+ 5V@300mA ;
PCI-7234:+ 5V@180mA (Built in DC-DC).
Working temperature: 0-60 ℃, storage: -20~80 ℃, humidity: 5%~95%, no condensation. The external dimensions vary, with PCI cards measuring 153mm × 107mm (7230) or 175mm × 107mm (7234), cPCI measuring 160mm × 100mm, and the low rise LPCI measuring only 120mm × 65mm, making it suitable for compact chassis.

Detailed explanation of hardware installation and connectors
3.1 Installation process
All 723X series cards are PCI plug and play devices, with standardized installation steps:
Turn off the power of the host and all peripherals, and unplug the power cord.
Open the chassis and select an available PCI/PCIe/cPCI slot (note that LPCI-7230 only supports 3.3V or 5V PCI, and LPCIe-7230 is x1 lane).
Touch the metal part of the chassis to release static electricity, grip the edge of the board and insert it into the slot to ensure firmness.
Secure the baffle with screws, close the chassis, and power on again.
After system startup, Windows (Vista/XP/2003/2000) or Linux will automatically detect new hardware and prompt for driver installation. ADLINK provides a new generation DAQPilot driver and SDK, while retaining traditional DASK drivers (such as PCIS-DASK), which users can choose according to their development environment. We strongly recommend new users to use DAQPilot, as its graphical interface and API encapsulation significantly shorten the development cycle.
3.2 Definition of connector pins (key differences)
PCI-7230: adopts a 37 pin D-type (DB-37) female socket, with pin definitions including IDI_1~IDI_15 (isolated input), IDO_2~IDO_15 (isolated output), EICOM (input common terminal, can be connected to common ground or common power supply), EOGND (output ground loop), VDD (output external power supply, 5-35V). Specifically, input channels 0 and 1 can serve as external interrupt sources.
CPCI-7230/LPCI-7230/LPCIe-7230: Using a 50 pin SCSI-II connector, in addition to the above signals, it adds IDI'nH/IDI_nL differential input pairs (for channels 8-15), supports differential mode to suppress common mode noise, and provides an additional ISO5V isolated power output (5V, which can supply power to external sensors).
PCI-7233: DB-37 interface, only includes IDI0~IDI-31 and I.GND (isolated common ground), without output related pins. Its dual interrupt sources correspond to COS events with low 16 bits (IDI_~15) and high 16 bits (IDI_ 16~31), respectively.
PCI-7234/7234P: DB-37 interface, only includes IDO0~IDO-31, I.GND, and VDD, without input channels. Note that 7234P is the source current output, and the external load needs to be connected between the output pin and ground, while 7234 is the sink current, and the load is connected between VDD and the output pin.
When actual wiring, it is necessary to use matching terminal blocks (such as ACLD-9137-01, DIN-37D-01 or DIN-50S-01) to simplify on-site wiring and provide reliable connection protection.
Register level programming and I/O control
Understanding register mapping is crucial for applications that require direct low-level control. All 723X series cards occupy a 32-bit base address in the I/O space (allocated by BIOS and can be obtained by reading the PCI configuration space offset of 18h). 32-bit (WORD) access must be used, 8-bit or 16 bit operations are prohibited, otherwise bus errors may occur.
4.1 Digital Input Register (Read Only)
The base addresses+0~+3 correspond to bytes 0~3, and each bit corresponds to an isolated input.
For the 7230 series: only use+0 and+1 (corresponding to IDI_1~IDI_15).
For 7233: Use+0~+3 (corresponding to IDI0~IDI-31).
Reading this register will obtain the current logic state of all input channels (1=high level, 0=low level).
4.2 Digital Output Register (Write Only)
Same base address+0~+3, each bit controls one isolated output.
The 7230 series uses+0 and+1 (IDO0~IDO-15).
7234/7234P uses+0~+3 (IDO0~IDO-31).
Writing 1 causes the corresponding output to conduct (for the sink current type, the output transistor is pulled low; for the source current type, the output transistor is pulled high to VDD).
When programming, it is important to note that the output register is write only and cannot read back the current output state. Therefore, the software needs to maintain a copy of the output image on its own.
4.3 Interrupt and COS detection (PCI-7233 only)
The unique advantage of PCI-7233 lies in its dual interrupt system, which allows edge change monitoring of 32 input channels. The internal hardware generates INT1 from the COS signal of the low 16 channels and INT2 from the high 16 channels. These two interrupts share the same IRQ line (allocated by BIOS), but their sources can be distinguished in ISR through status registers.
COS detection principle: The rising and falling edges of each input channel are captured. Once a jump occurs, the corresponding interrupt request is latched until the software call clears the interrupt function (such as _7233_CLR-IRQ) before being released. This mechanism is very suitable for scenarios that require immediate response to changes in switch values, such as emergency stop signals, safety door status, flow meter pulses, etc., without the need for continuous CPU polling, significantly reducing system overhead.

Detailed explanation of isolated input-output circuits and external wiring specifications
5.1 Input Circuit
The input terminals of 7230 and 7233 use optocouplers, with 1.2k Ω current limiting resistors connected in series internally. External signals can be connected in a "common ground" or "common source" manner, depending on the EICOM pin connection:
Common ground mode: EICOM is connected to the external power supply ground, and the input signal is connected to IDI-n. When the signal is high (5~24V), the optocoupler conducts and the input register reads logic 1.
Common source mode: EICOM is connected to the positive pole of an external power supply. When the input signal is pulled down to ground by an external switch, the optocoupler conducts.
For the differential channel (IDI_nH/IDI_nL) of cPCI-7230/LPCI-7230/LPCIe-7230, it is more suitable for long-distance transmission or high noise environments, effectively suppressing common mode interference.
5.2 Output Circuit
The output terminal is a Darlington transistor. When the output is logic 1, the internal transistor of the current sink type (7230/7234) conducts, pulling the output pin to EOGND (i.e. low level), and the load current flows from VDD through the load into the pin. The source current type (7234P) is the opposite. When logic 1 is applied, the pin outputs a high level (close to VDD), and the current flows from the pin through the load to the external ground.
In addition to providing load current, the VDD pin is also internally connected to a freewheeling diode (flywheel diode). When driving inductive loads such as relay coils and solenoid valves, this diode provides a discharge circuit for the reverse induced electromotive force at the moment of turn off, protecting the output transistor from breakdown. It is necessary to provide an external power supply of 5-35V for VDD, and the common ground of the power supply must be connected to EOGND (sink current type) or to the external load ground (source current type).
Typical application example: The 7234 output drives a 24V relay, with VDD connected to 24V+. One end of the relay coil is connected to VDD and the other end is connected to IDO-n. When the output is 1, the coil is energized and pulled in. For 7234P, one end of the coil is connected to IDO-n and the other end is connected to 24V -, with the same logic 1 driving.
Software Ecology and Development Support
ADLINK provides multi-level software resources for the 723X series:
DAQPilot (Next Generation Driver/SDK): Unified API interface, supports ActiveX and. NET Assembly, graphical configuration tool DAQMaster, can quickly generate test tasks. It is recommended that all new projects prioritize its use.
Traditional DASK drivers: PCIS-DASK is suitable for Windows (including Vista 64 bit), and PCIS-DASK/X is suitable for Linux. These drivers have been validated for a long time and have rich APIs, making them suitable for maintenance projects with existing code bases.
Third party integration:
MATLAB: Use the Data Acquisition Toolbox directly through the DAQ-MTLBB adapter.
LabVIEW: DAQ View PnP VI library, fully compatible with NI style, supports LabVIEW 7.0 to 8.5.
Agilent VEE: PICS-VEE driver package seamlessly integrated into the VEE environment.
ActiveX Control DAQBench: Used for SCADA/HMI development, supports VB, VC++, Delphi, etc.
DAQCreator: Non programming data acquisition software that supports real-time display, FFT analysis, and streaming (up to 40MB/s), suitable for fast validation.
Troubleshooting and Common Problems
The system cannot recognize the new card: check if the PCI/PCIe slot is in good contact and try replacing the slot; Confirm that the PCI resource allocation in the motherboard BIOS is not turned off; Verify if the card is compatible with the operating system (e.g. LPCIe-7230 requires PCIe x1 slot).
Read the input value as always 0 or 1: Check the external wiring and confirm that the EICOM connection is correct; Measure whether the input voltage is within the effective range (5~24V is high, 0~1.5V is low); If differential input is used, ensure that the potential difference between the H/L terminals meets the requirements.
Output unable to drive load: Check if the VDD power supply is normal and if the voltage is below the rated load value; For the current injection type, confirm that the load is connected between VDD and the output pin; For the source current type, confirm that the load is connected between the output pin and ground; Measure whether the voltage drop during output conduction is too large (the saturation voltage drop of Darlington tube is about 1V).
Interrupt not triggered (PCI-7233): Confirm that there is a level change in the input channel; Check if the interrupt clearing function is correctly called (if not cleared, the latch signal will prevent subsequent interrupts); Verify that the BIOS has assigned a valid IRQ and that ISR is correctly registered in the driver.
Serious overheating of the board: Check if the total output current exceeds the rated value, especially when multiple channels are conducting simultaneously with high duty cycle, and reduce the rating; Reduce the number of simultaneously conductive paths or increase heat dissipation appropriately.
