ADLINK 7230 Series Isolation DIO Card Selection and Engineering Application Guide

The 7230/7234 output adopts a Darlington transistor array, providing high current driving capability. Its output methods are divided into two types:

Sink current: PCI-7234 (and 7230 output side). When the output is logic 1, the output terminal (OUT) conducts to ground (equivalent to NPN transistor saturation), and one end of the external load is connected to the positive power supply, while the other end is connected to the OUT terminal. The current flows from the positive power source → load → OUT → ground, that is, "pours" into the chip.

Source current: PCI-7234P. The output terminal (OUT) is conductive to the positive power supply (equivalent to a PNP transistor), with one end of the load connected to OUT and the other end connected to ground. The current flows from OUT → load → ground, that is, the "source" comes out of the chip.

Selection criteria:

If one end of your load (such as a relay coil) is connected to common ground, it needs to be driven with positive voltage → select the current type (7234).

If one end of the load is already connected to the common positive pole (24V+), it is necessary to use a low-level drive ->select the source current type (7234P).

4.2 Current drive capability and duty cycle limitations (be sure to pay attention!)

The manual provides a very detailed relationship between current and duty cycle, which is a trap that is easily overlooked in engineering design and can lead to chip overheating and damage.

For PCI-7230/7234 (current sink):

Single channel maximum 500mA (100% duty cycle continuous conduction).

But when all 32 channels are simultaneously open:

PCI-7234: The maximum total current is limited to 500mA/channel @ 20% duty cycle (i.e. pulse mode). If it is DC normally open, it needs to be reduced to about 130mA/channel (50% duty cycle) or 370mA/channel (10% duty cycle).

The output side (16 channels) of PCI-7230 is similar, and the manual states: single channel 500mA@100 %When all channels are conducting simultaneously, it is recommended to use 370mA at a 10% duty cycle or 130mA at a 50% duty cycle.

For PCI-7234P (source current):

single channel 500mA@100 %Duty cycle.

When all 32 channels are conducting simultaneously, the total current at a 10% duty cycle is 260mA (i.e. an average of about 8mA per channel), which is much lower than the current sink type because the source current adopts PNP structure, resulting in higher power consumption.

Power consumption budget:

The maximum power consumption of the chip for every 8 DO channels is 1.47W (7230/7234P) or 2.25W (7234).

In engineering, the total power consumption must be calculated based on the actual total current and duty cycle to ensure that it does not exceed the heat dissipation capacity of the board (operating temperature 0~60 ℃).

Practical advice:

If multiple DC relays (coil current of about 30-50mA) need to be driven, 10-20 channels can be turned on simultaneously, but the total power consumption must be calculated. If necessary, external intermediate relays or solid-state relays can be used for expansion to reduce the burden on the board.

For frequent on-off situations (such as PWM control), using pulse mode (low duty cycle) can significantly increase the allowable current.

4.3 Requirements for External Power Supply

Isolation output requires external power supply (5-35VDC), isolated from the PC power supply, provided by the user. Note:

PCI-7230 requires external DC power supply (not just power from PCI).

PCI-7234 has an internal DC-DC converter, but still requires external driving voltage (the manual does not specify whether it is fully self powered, actual wiring needs to refer to pin definitions).

Connectors and Cable Accessories - Quickly Build Test System

According to different bus forms, connectors vary:

Model, connector type, matching terminal board, matching cable

PCI-7230/7233/7234/7234P 37 pin D-sub female head DIN-37D-01 (rail installation), ACLD-9137-01 (universal) ACL-10137-1MM (1 meter, male to male)

LPCI-7230/LPCIe-7230/cPCI-7230 50 pin SCSI-II female head DIN-50S-01 (rail installation) ACL-10250-1 (1 meter, 50 cores)

Wiring prompt:

Use DIN-37D-01 terminal board with clear silk screen markings indicating DI/DO correspondence, and equipped with screw terminals for easy on-site wiring.

For SCSI interfaces, attention should be paid to compact signal arrangement, and it is recommended to use original crimping cables to avoid poor contact.

Software and driver support - worry free across platforms

ADLINK provides a complete driving ecosystem:

Windows: PICS-DASK (traditional) and DAQPilot (new generation recommendation), supporting LabVIEW (DAQPilot for LabVIEW) and MATLAB (DAQ-MTTLB).

Linux：PCIS-DASK/V。

Development languages: VB.net/VC.net/VB/VC++/BBB/Delphi, with accompanying AD Loger data recording software and DAQBench visualization control.

Important reminder: New projects should prioritize using the DAQPilot driver, which provides graphical guidance and a unified API, greatly shortening the development cycle. Although the old version of DASK driver is still available, it is no longer recommended.

Key points of engineering wiring and anti-interference practice