RS-232、RS-422与RS-485都是（）。A、并行数据接口标准B、串行数据接口标准C、单向发送的D、双向发送的
RS-232、RS-422与RS-485都是（）。
- A、并行数据接口标准
- B、串行数据接口标准
- C、单向发送的
- D、双向发送的
相关考题：
下面关于UART、RS-232、RS-485的叙述中，错误的是（）。A.基于UART可以构成RS-232接口B.基于UART不能构成RS-485接口C.RS-232接口标准的最长通信距离为15mD.通过RS-485可构成主从式多机通信系统，主机可采用轮询方式与各从机建立通信连接
下面关于RS-232和RS-485的叙述中，正确的是（）。A、RS-485采用负逻辑传输：+3V~+15V时为逻辑0，-15V~-3V时为逻辑1B、RS-232采用差分信号传输方式C、RS-485的传输距离比RS-232远D、RS-232的传输速率比RS-485高
A pSeries technical specialist is performing a solutions assurance with a customer for a new single-frame 10-node p655 system being attached to a currently installed HMC. Which of the following questions should be asked to gather all the required information to determine whether the p655 solution can connect to the HMC？（）A、Are there at least ten RS-232 ports available on the HMC？B、Are there at least ten RS-422 ports available on the HMC？C、Are there at least ten RS-232 and two RS-422 ports available on the HMC？D、Are there at least two RS-232 and ten RS-422 ports available on the HMC？
下面关于UART、RS-232、RS-485的叙述中，错误的是（）。A、基于UART可以构成RS-232接口和RS-485接口B、RS-485接口标准的最长通信距离与RS-232接口标准的最长通信距离相当C、RS-485标准采用差分信号传输方式，因此具有很强的抗共模干扰能力D、通过RS-485可构成主从式多机通信系统，主机可采用轮询方式与各从机建立通信连接
单选题下面关于UART、RS-232、RS-485的叙述中，错误的是（）。A基于UART可以构成RS-232接口和RS-485接口BRS-485接口标准的最长通信距离与RS-232接口标准的最长通信距离相当CRS-485标准采用差分信号传输方式，因此具有很强的抗共模干扰能力D通过RS-485可构成主从式多机通信系统，主机可采用轮询方式与各从机建立通信连接
单选题A pSeries technical specialist is performing a solutions assurance with a customer for a new single-frame 10-node p655 system being attached to a currently installed HMC. Which of the following questions should be asked to gather all the required information to determine whether the p655 solution can connect to the HMC？（）AAre there at least ten RS-232 ports available on the HMC？BAre there at least ten RS-422 ports available on the HMC？CAre there at least ten RS-232 and two RS-422 ports available on the HMC？DAre there at least two RS-232 and ten RS-422 ports available on the HMC？