Installation guide

PicoScope 4000 Series (A API) Programmer's Guide 5

3 Programming with the PicoScope 4000 Series (A

API)

The ps4000a.dll dynamic link library in your PicoScope installation directory allows

you to program a PicoScope 4000 Series oscilloscope using standard C function calls.

A typical program for capturing data consists of the following steps:

Open the scope unit.

Set up the input channels with the required voltage ranges and coupling mode.

Set up triggering.

Start capturing data. (See Sampling modes, where programming is discussed in

more detail.)

Wait until the scope unit is ready.

Stop capturing data.

Copy data to a buffer.

Close the scope unit.

Numerous sample programs are installed with your PicoScope software. These show

how to use the functions of the driver software in each of the modes available.

3.1

Driver

Your application will communicate with a PicoScope 4000 API driver called

ps4000a.dll. The driver exports the PicoScope 4000 function definitions in

standard C format, but this does not limit you to programming in C. You can use the

API with any programming language that supports standard C calls.

The API driver depends on a kernel driver, CyUSB3.sys, which has a 64-bit version

and a 32-bit version and works with all operating systems except Windows 8. Windows

8 uses WinUsb.sys on both 32-bit and 64-bit versions. Your application does not

need to call the kernel driver. Once you have installed the PicoScope 6 software,

Windows automatically installs the kernel driver when you plug in the PicoScope 4000

Series PC Oscilloscope for the first time.

3.2

Voltage ranges

The ps4000aSetChannel function allows you to set the voltage range of each input

channel of the scope. The allowable voltage ranges are described in the device data

sheet. Each sample is normalized to 16 bits between maximum and minimum values

that are defined as constants and can also be queried by calling two functions:

Constant

Function

Voltage

PS4000A_MAX_VALUE

ps4000aMaximumValue

maximum

PS4000A_MIN_VALUE

ps4000aMinimumValue

minimum

PS4000A_LOST_DATA

[1]

Note 1. In streaming mode, this special value indicates a buffer overrun.