代码基本逻辑
业务逻辑：我要给plc传一个值a=7，我要去检验plc有没有收到这个值，如果没有收到这个值，我要再传一遍值，直到plc里真的收到这个值了
简洁版：循环发送值直到PLC接收到指定值为止
代码逻辑：一直发a的值给plc，检查plc有没有收到
import snap7
def check_plc_value(ip_address, value):
# Snap7连接PLC
plc = snap7.client.Client()
plc.connect(ip_address, 0, 1)
# 循环发送值直到PLC接收到指定值为止
while True:
# 发送值到PLC
plc.db_write(1, 0, [value])
# 读取DB块的值
db_data = plc.db_read(1, 0, 1)
db_value = snap7.util.get_int(db_data, 0)
if db_value == value:
# 当PLC接收到指定值时，退出循环
print("PLC received the value successfully.")
break
else:
# 当PLC没有接收到指定值时，继续发送值
print("PLC did not receive the value, sending again...")
# 断开连接
plc.disconnect()
import snap7
def connect_plc(ip_address):
# Snap7连接PLC
plc = snap7.client.Client()
plc.connect(ip_address, 0, 1)
return plc
def send_value_to_plc(plc, db_number, start_address, value):
# 将值写入DB块
plc.db_write(db_number, start_address, snap7.util.to_byte(value))
def check_value_received(plc, db_number, start_address, expected_value):
# 检查PLC是否收到了值
db_data = plc.db_read(db_number, start_address, 2)
received_value = snap7.util.get_int(db_data, 0)
return received_value == expected_value
# 使用示例
plc = connect_plc('192.168.1.100')
db_number = 1
start_address = 0
value = 7
while True:
# 将值写入PLC
send_value_to_plc(plc, db_number, start_address, value)
# 检查PLC是否收到了值
if check_value_received(plc, db_number, start_address, value):
print("PLC received the value successfully.")
break
else:
print("PLC didn't receive the value, retrying...")