Creating an Mqtt client instance requires several parameters including a unique client ID, a broker IP address and port, and the optional MqttProperties object described previously.
创建Mqtt客户实例需要几个参数，包括一个惟一客户机id、代理ip地址和端口以及可选的MqttProperties对象。
DB9M-to-USB cable (optional if your host platform has an RS-232 port).
DB9M - to - US b线缆(如果主机平台有RS- 232端口，它就是可选的)。
The firm plans to offer optional solar-photoelectric systems, to be set up as a car port at home, that will be able to power the cars for 80km a day without having to draw on the grid.
公司计划提供光电转能系统，即未来的太阳能车房能实现电驱车不必从电网取电一天跑80公里了。
The gas burner may include an optional flame tube with an optional exhaust port in which a flame is contained and sequestered from diffusing air.
气体燃烧器可以包括可选的火焰管，该火焰管有可选的排出口，火焰包含于该火焰管中，并与扩散空气隔开。
The gas entry port may include an optional one-way valve.
气体输入口可包括可选的单向阀。
Pneumatic fluid power - Five-port directional control valves - Part 2 : mounting interface surfaces with optional electrical connector.
气压液动。五通方向控制阀。第2部分：任选电气连接器的安装接口面。
No module port provided (optional), able to use patch panel tubular dust cover, beautiful in matching.
不配备模块端口（可选择），可以使用配线架空口防尘盖板，配合美观；
No module port provided (optional), able to use patch panel tubular dust cover, beautiful in matching.
不配备模块端口（可选择），可以使用配线架空口防尘盖板，配合美观；
应用推荐