TRICONEX 3664 双数字输出模块 双数字输出 （DDO） 模块沿单个并行或串联路径接收来自主处理器的输出信号

双数字输出 （DDO） 模块沿单个并行或串联路径接收来自主处理器的输出信号，并对每个交换机分别应用三选二投票过程。开关产生一个输出信号，然后传递到现场端接。TMR 模块上的四路输出电路为所有关键信号路径提供多个冗余，而双电路提供足够的冗余以确保安全操作。双模块针对低成本比大可用性更重要的安全关键型控制程序进行了优化。双数字输出模块具有电压环回电路，可独立于负载的存在来验证每个输出开关的运行，并确定是否存在潜在故障。如果检测到的现场电压与输出点的命令状态不匹配，则会激活负载/保险丝报警指示灯。此外，对双数字输出模块的每个通道和电路执行持续诊断。任何通道上的任何诊断失败都会激活故障指示灯，进而激活机箱报警信号。双模块在存在大多数单个故障的情况下可以正常工作，并且在某些类型的多个故障中可以正常工作，但卡住OFF故障是一个例外。如果其中一个输出开关出现卡住 OFF 故障，则输出将进入 OFF 状态，并且在切换到热备盘模块期间可能会出现毛刺。双数字输出模块支持热备盘功能，允许在线更换故障模块。每个模块都采用机械键控，以防止在配置的机箱中安装不当。双数字输出模块需要一个单独的外部端接面板（ETP），该面板带有连接到Tricon背板的电缆接口。数字输出设计用于为现场设备提供电流，因此现场电源必须连接到现场终端上的每个输出点。

The Dual Digital Output (DDO) module receives output signals from the main processor along a single parallel or series path and applies a two out of three voting process to each switch. The switch generates an output signal that is then transmitted to the field termination. The four output circuits on the TMR module provide multiple redundancy for all critical signal paths, while the dual circuits provide sufficient redundancy to ensure safe operation. Dual modules have been optimized for safety critical control programs that are more important than maximum availability at low cost. The dual digital output module has a voltage loop circuit that can verify the operation of each output switch independently of the presence of the load and determine if there are potential faults. If the detected on-site voltage does not match the command status of the output point, the load/fuse alarm indicator light will be activated. In addition, continuous diagnosis is performed on each channel and circuit of the dual digital output module. Any diagnostic failure on any channel will activate the fault indicator light, which in turn activates the chassis alarm signal. Dual modules can function normally in the presence of most individual faults, and can function normally in certain types of multiple faults, with the exception of stuck OFF faults. If one of the output switches experiences a stuck OFF fault, the output will enter the OFF state and burrs may appear during switching to the hot spare module. The dual digital output module supports the hot spare function and allows for online replacement of faulty modules. Each module adopts mechanical keying to prevent improper installation in the configured chassis. The dual digital output module requires a separate external termination panel (ETP) with cable interfaces connected to the Tricon backplane. The digital output is designed to provide current to on-site devices, so the on-site power supply must be connected to each output point on the on-site terminal.