HIMA F8627处理器模块,F8627使用指导
RS-485多单元（单个或一半）需要多点握手双工）或单单元半双工配置。这将启用传输驱动器
仅当RTU正在传输时。对于RS-232，该模式控制CT与可操作的RS232-to-RS485转换器兼容的信号在半双工模式下。启用多点握手时，没有其他可以握手。
无线电调制解调器-类似于硬件握手，但RTS仅被断言当RTU有数据要发送时。此后，RTU发送或暂停数据基于CTS线路的传输。
无线电调制解调器模式还提供可选的调制解调器掉头计时器
HIMA F8627处理器模块（TAT）。如果调制解调器在指定的时间段内没有响应RTS线路，则会刷新传输缓冲区，丢弃RTS并丢失帧。TAT是通过在配置中指定0.25、50、75和1.00之一启用第二）时间间隔。将时间间隔设置为无将禁用TAT。3.5 DCS主动检测
RTU接口模块提供了选择性监测Modbus活动的能力主人如果该活动下降，则在配置的%I参考（位0）和Modbus异常状态字节；此外，DCS LED将开始以1秒的速度闪烁。这为CPU、维护操作员和主机提供一种方法，以确定主机是否功能正常。
要启用此功能，请将DCS配置条目设置为您希望RTU模块的时间量在设置指示位之前，等待发送最后一个通信帧。超时值为限制为1到12秒。将超时值设置为零将禁用此功能。
Multi-drop handshaking is required for RS-485 multiple unit (either single or half
duplex) or single unit half-duplex configurations. This enables the transmit driver
only when the RTU is transmitting. For RS-232, this mode controls the CTS
signal for compatibility with RS232-to-RS485 converters which can be operated
in a half-duplex mode. When multi-drop handshaking is enabled, no other
handshaking is available.
RADIO MODEM - Similar to hardware handshaking with the exception that RTS is only asserted
when the RTU has data to send. Thereafter, the RTU sends or suspends data
transfer based on the CTS line.
The radio modem mode also provides an optional modem turn-around-timer
(TAT). If the modem does not respond to the RTS line within a specified period,then the transmit buffer is flushed, RTS is dropped and the frame is lost. TAT is
enabled by specifying in the confi guration one of the (.25, .50, .75 and 1.00
Second) time intervals. Setting the time interval to NONE disables the TAT.
3.5 DCS Active Detection
The RTU Interface Module provides the capability to optionally monitor the activity from the Modbus
master. Should that activity drop off, a bit is set in both the configured %I reference (Bit 0) and the
Modbus exception status byte; furthermore, the DCS LED will begin to flash at a 1 second rate. This
provides a method for the CPU, maintenance operator and the master to determine if the master is
functioning properly.
To enable this feature, set the DCS configuration entry to the amount of time you wish the RTU Module to
wait after the last communications frame was sent before setting the indication bit. Th e time-out value is
limited to 1 through 12 Seconds. Setting the Time-out value to zero disables this feature.
