LineScanSoftwareTrigger.py

Software Trigger of Line Scan Camera

It shows how to set software trigger of line scan cameras.

# -- coding: utf-8 --

import sys
import platform
import os
import threading
import time


# Compatible with different operating systems to load DDL
currentsystem = platform.system()
if currentsystem == 'Windows':
    sys.path.append(os.path.join(os.getenv('MVCAM_COMMON_RUNENV'), "Samples", "Python", "MvImport"))
else:
    sys.path.append(os.path.join("..", "..", "MvImport"))
from MvCameraControl_class import *

# Compatible with input processing of Python 2.X and 3.X
if sys.version_info[0] < 3: 
    # Python 2.x
    input_func = raw_input
else: 
    # Python 3.x
    input_func = input

# Decoding Characters
def decoding_char(ctypes_char_array):
    """
    Safely decode a string from a ctypes character array.
    Compatible with Python 2.x and 3.x, as well as 32-bit and 64-bit environments.
    """
    byte_str = memoryview(ctypes_char_array).tobytes()
    
    # Truncate at the first null character
    null_index = byte_str.find(b'\x00')
    if null_index != -1:
        byte_str = byte_str[:null_index]
    
    # Attempt to decode using multiple encodings
    for encoding in ['gbk', 'utf-8', 'latin-1']:
        try:
            return byte_str.decode(encoding)
        except UnicodeDecodeError:
            continue
    
    # If all encodings fail, use a replacement strategy
    return byte_str.decode('latin-1', errors='replace')
    

g_exit = False
fun_ctype = get_platform_functype()

stFrameInfo = POINTER(MV_FRAME_OUT_INFO_EX)
pData = POINTER(c_ubyte)
FrameInfoCallBack = fun_ctype(None, pData, stFrameInfo, c_void_p)

def image_callback(pData, pFrameInfo, pUser):
        stFrameInfo = cast(pFrameInfo, POINTER(MV_FRAME_OUT_INFO_EX)).contents
        if stFrameInfo:
            print("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (stFrameInfo.nWidth, stFrameInfo.nHeight, stFrameInfo.nFrameNum))


CALL_BACK_FUN = FrameInfoCallBack(image_callback)


# Send software trigger command
def software_trigger_thread(cam_ins=0, cmd_value=""):
    while True:
        res = cam.MV_CC_SetCommandValue(cmd_value)
        if res != 0:
            print("set software trigger command fail[0x%x]" % res)
        time.sleep(1)
        if g_exit is True:
            break


def check_feature_node_access(cam_ins, node_name):
    access_mode = MV_XML_AccessMode()
    res = cam_ins.MV_XML_GetNodeAccessMode(node_name, access_mode)
    if res != 0:
        return False
    if access_mode == AM_WO or access_mode == AM_RO or access_mode == AM_RW:
        return True
    else:
        return False


if __name__ == "__main__":

    try:
        # Initialize SDK resources
        MvCamera.MV_CC_Initialize()

        SDKVersion = MvCamera.MV_CC_GetSDKVersion()
        print ("SDKVersion[0x%x]" % SDKVersion)
    
        deviceList = MV_CC_DEVICE_INFO_LIST()
        tlayerType = (MV_GIGE_DEVICE | MV_USB_DEVICE | MV_GENTL_CAMERALINK_DEVICE
                      | MV_GENTL_CXP_DEVICE | MV_GENTL_XOF_DEVICE)

        # Enumerate devices
        ret = MvCamera.MV_CC_EnumDevices(tlayerType, deviceList)
        if ret != 0:
            print("enum devices fail! ret[0x%x]" % ret)
            sys.exit()

        if deviceList.nDeviceNum == 0:
            print("find no device!")
            sys.exit()

        print("Find %d devices!" % deviceList.nDeviceNum)

        for i in range(0, deviceList.nDeviceNum):
            mvcc_dev_info = cast(deviceList.pDeviceInfo[i], POINTER(MV_CC_DEVICE_INFO)).contents
            if mvcc_dev_info.nTLayerType == MV_GIGE_DEVICE or mvcc_dev_info.nTLayerType == MV_GENTL_GIGE_DEVICE:
                print ("\ngige device: [%d]" % i)
                strModeName = decoding_char(mvcc_dev_info.SpecialInfo.stGigEInfo.chModelName)
                print ("device model name: %s" % strModeName)
                strSerialNumber = decoding_char(mvcc_dev_info.SpecialInfo.stGigEInfo.chSerialNumber)
                print("device serial number: %s" % strSerialNumber)
                nip1 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0xff000000) >> 24)
                nip2 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x00ff0000) >> 16)
                nip3 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x0000ff00) >> 8)
                nip4 = (mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x000000ff)
                print ("current ip: %d.%d.%d.%d\n" % (nip1, nip2, nip3, nip4))
            elif mvcc_dev_info.nTLayerType == MV_USB_DEVICE:
                print ("\nu3v device: [%d]" % i)
                strModeName = decoding_char(mvcc_dev_info.SpecialInfo.stUsb3VInfo.chModelName)
                print ("device model name: %s" % strModeName)

                strSerialNumber =  decoding_char(mvcc_dev_info.SpecialInfo.stUsb3VInfo.chSerialNumber)                
                print ("device serial number: %s" % strSerialNumber)
            elif mvcc_dev_info.nTLayerType == MV_GENTL_CAMERALINK_DEVICE:
                print ("\nCML device: [%d]" % i)
                strModeName = decoding_char(mvcc_dev_info.SpecialInfo.stCMLInfo.chModelName)
                print ("device model name: %s" % strModeName)

                strSerialNumber = decoding_char(mvcc_dev_info.SpecialInfo.stCMLInfo.chSerialNumber)
                print ("device serial number: %s" % strSerialNumber)
            elif mvcc_dev_info.nTLayerType == MV_GENTL_CXP_DEVICE:
                print ("\nCXP device: [%d]" % i)
                strModeName =  decoding_char(mvcc_dev_info.SpecialInfo.stCXPInfo.chModelName)
                print ("device model name: %s" % strModeName)
                
                strSerialNumber =  decoding_char(mvcc_dev_info.SpecialInfo.stCXPInfo.chSerialNumber)
                print ("device serial number: %s" % strSerialNumber)
            elif mvcc_dev_info.nTLayerType == MV_GENTL_XOF_DEVICE:
                print ("\nXoF device: [%d]" % i)
                strModeName =  decoding_char(mvcc_dev_info.SpecialInfo.stXoFInfo.chModelName)
                print ("device model name: %s" % strModeName)

                strSerialNumber =  decoding_char(mvcc_dev_info.SpecialInfo.stXoFInfo.chSerialNumber)
                print ("device serial number: %s" % strSerialNumber)

        nConnectionNum = input_func("please input the number of the device to connect:")

        if int(nConnectionNum) >= deviceList.nDeviceNum:
            print("input error!")
            sys.exit()

        # Create a camera instance
        cam = MvCamera()

        # Select a device, and create a handle
        stDeviceList = cast(deviceList.pDeviceInfo[int(nConnectionNum)], POINTER(MV_CC_DEVICE_INFO)).contents

        ret = cam.MV_CC_CreateHandle(stDeviceList)
        if ret != 0:
            raise Exception("create handle fail! ret[0x%x]" % ret)

        # Turn on the device
        ret = cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
        if ret != 0:
            raise Exception("open device fail! ret[0x%x]" % ret)

        # Get optimal packet size (only supported by GigE devices)
        if stDeviceList.nTLayerType == MV_GIGE_DEVICE or stDeviceList.nTLayerType == MV_GENTL_GIGE_DEVICE:
            nPacketSize = cam.MV_CC_GetOptimalPacketSize()
            if int(nPacketSize) > 0:
                ret = cam.MV_CC_SetIntValue("GevSCPSPacketSize", nPacketSize)
                if ret != 0:
                    print("Warning: Set Packet Size fail! ret[0x%x]" % ret)
            else:
                print("Warning: Get Packet Size fail! ret[0x%x]" % nPacketSize)

        # Pre-set frame trigger of line scan camera
        ret = cam.MV_CC_SetEnumValueByString("ScanMode", "FrameScan")
        if ret == 0:
            print("set frame scan mode")

        # Check if FrameTriggerControl is readable
        if check_feature_node_access(cam, "FrameTriggerControl"):
            # Set trigger mode to on
            ret = cam.MV_CC_SetBoolValue("FrameTriggerMode", True)
            if ret != 0:
                raise Exception("set frame trigger mode on fail! ret[0x%x]" % ret)
            # Set trigger source to Line0
            ret = cam.MV_CC_SetEnumValueByString("FrameTriggerSource", "Software")
            if ret != 0:
                raise Exception("set trigger source Software fail! ret[0x%x]" % ret)

            trigger_cmd = "FrameTriggerSoftware"
        else:
            # Set trigger selector to FrameBurstStart
            ret = cam.MV_CC_SetEnumValue("TriggerSelector", 6)
            if ret != 0:
                raise Exception("set trigger selector fail! ret[0x%x]" % ret)

            # Set trigger mode to on
            ret = cam.MV_CC_SetEnumValue("TriggerMode", 1)
            if ret != 0:
                raise Exception("set trigger mode fail! ret[0x%x]" % ret)

            # Set trigger source to Line0
            ret = cam.MV_CC_SetEnumValueByString("TriggerSource", "Software")
            if ret != 0:
                raise Exception("set trigger source fail! ret[0x%x]" % ret)

            trigger_cmd = "TriggerSoftware"

        #Register an image grabbing callback
        ret = cam.MV_CC_RegisterImageCallBackEx(CALL_BACK_FUN, None)
        if ret != 0:
            raise Exception("register image callback fail! ret[0x%x]" % ret)

        # Start grabbing images
        ret = cam.MV_CC_StartGrabbing()
        if ret != 0:
            raise Exception("start grabbing fail! ret[0x%x]" % ret)

        try:
            hThreadHandle = threading.Thread(target=software_trigger_thread, args=(cam, trigger_cmd))
            hThreadHandle.start()
        except:
            print("error: unable to start thread")

        print ("press Enter key to stop grabbing.")
        input_func()
        
        g_exit = True
        hThreadHandle.join()

        # Stop grabbing images
        ret = cam.MV_CC_StopGrabbing()
        if ret != 0:
            raise Exception("stop grabbing fail! ret[0x%x]" % ret)

        # Turn off the device
        ret = cam.MV_CC_CloseDevice()
        if ret != 0:
            raise Exception("close device fail! ret[0x%x]" % ret)

        # Destroy the handle
        cam.MV_CC_DestroyHandle()

    except Exception as e:
        print(e)
        cam.MV_CC_CloseDevice()
        cam.MV_CC_DestroyHandle()
    finally:
        # Release SDK resources
        MvCamera.MV_CC_Finalize()