A-B 1746-HS具有先进技术允许在实际应用中将分布式结构移动到危险的区域。我们已经从标准的FLEX I/O系统中吸取经验并利用该套系统来建立一个外表、感觉都相同，且用法简单的本质安全系统。

在危险区域安装时无需进行净化和安装防爆外壳。FLEX Ex是一个既不需要本质安全防护，也无需用长距离布线将模块连接到控制柜的模块化I/O系统。

一个适配器最多可以同8个I/O模块通讯。允许将适配器连接到：

 128个数字量输入/输出，

 64个模拟量输入，

 数模混合来满足用户的要求。

冗余介质ControlNet适配器最多可以同8个I/O模块通讯并能被安装在危险区域里。可调节键形开关防止不正确的模块插入到预先配置的端子基座内。更换端子基座时不需要移动系统里的其它基座。FLEX Ex电源连接到端子基座上为I/O模块和现场设备供电。不需要连接附加的电源。将I/O模块插入端子基座来连接I/O总线和现场设备。

可带电插拔模块。不直接接线到模块使用户在更换模块时，不需断开现场设备接线或系统电源。可混合并匹配使用I/O模块。很多种类的模块，包括数字量、模拟量、温度、频率及HART模块。FLEXbus Isolator允许连接到标准FLEX I/O适配器和I/O上，这样也提供了选择其它网络的可能。

在所有模块上的涂层保护使得模块满足ISA-S71.04-1985严格的标准G3关于有害气体的要求，这些有害气体包括硫化氢、二氧化硫、氯气、二硫化氮、氟化氢、氨和臭氧。

FLEX Ex结合了端子排和I/O接口的本质安全隔离。用这个端子基座上的接线排把现场设备直接连接起来。FLEX Ex的设计还有以下的特点：

 分布式本质安全系统的模块化

 一个更大、基于导轨的系统的所有特性

 在现场附近安装节省了电缆费用并降低了布线复杂程度

 现场线缆终端不需要接线柜和额外的端子排

 使用ControlNet EX产品完成的基于ControlNet的网络解决方案

 DIN导轨安装

如果系统出现问题，FLEX EX能提供额外价值。端子基座使用户能够在不需要对系统进行重新布线和中断系统的前提下对I/O模块进行带电插拔。将现场布线端子与本质安全隔离、I/O接口组合在同一位置使得系统维护变得简单，从而节省了时间和费用。更多的好处包括：

 I/O背板、输入电路和电源之间电流隔离

 双重故障保护的本质安全电路提供了最高的容错能力

 I/O线路提供了完全的本质安全现场设备保护

 这些模块本身是本安防护的，可安装在恶劣环境下

FLEX Ex模块可以进行带电插拔。FLEX Ex网络模块的维护和线路连接可以在危险的区域进行，并且此时系统正工作在恶劣的环境下。

FLEX Ex has advanced technology that allows for the movement of distributed structures to hazardous areas in practical applications. We have learned from the standard FLEX I/O system and utilized it to establish an intrinsically safe system that looks and feels the same, and is easy to use.

When installing in hazardous areas, there is no need for purification or installation of explosion-proof enclosures. FLEX Ex is a modular I/O system that neither requires intrinsic safety protection nor long-distance wiring to connect modules to the control cabinet.

An adapter can communicate with up to 8 I/O modules. Allow adapter to be connected to:

128 digital inputs/outputs,

64 analog inputs,

Digital analog mixing to meet user requirements.

Redundant media ControlNet adapters can communicate with up to 8 I/O modules and can be installed in hazardous areas. Adjustable key switches prevent incorrect module insertion into the pre configured terminal base. When replacing the terminal base, there is no need to move other bases in the system. The FLEX Ex power supply is connected to the terminal base to power the I/O module and field devices. No additional power supply needs to be connected. Insert the I/O module into the terminal base to connect the I/O bus and field devices.

Powered plug-in module. Not directly wired to the module allows users to replace the module without disconnecting the on-site device wiring or system power supply. I/O modules can be mixed and matched for use. There are many types of modules, including digital, analog, temperature, frequency, and HART modules. FLEXbus Isolator allows connection to standard FLEX I/O adapters and I/O, which also provides the possibility of selecting other networks.

The coating protection on all modules ensures that the modules meet the strict requirements of ISA-S71.04-1985 standard G3 for harmful gases, including hydrogen sulfide, sulfur dioxide, chlorine gas, nitrogen disulfide, hydrogen fluoride, ammonia, and ozone.

FLEX Ex combines intrinsic safety isolation of terminal strips and I/O interfaces. Connect the on-site equipment directly using the wiring strip on this terminal base. The design of FLEX Ex also has the following characteristics:

Modularization of Distributed Intrinsic Safety Systems

All characteristics of a larger, rail based system

Installing near the site saves cable costs and reduces wiring complexity

On site cable terminations do not require wiring cabinets or additional terminal strips

A ControlNet based network solution completed using ControlNet EX products

DIN rail installation

If there are system issues, FLEX EX can provide additional value. The terminal base allows users to plug and unplug I/O modules with power without the need to rewire and interrupt the system. Combining on-site wiring terminals with intrinsically safe isolation and I/O interfaces in the same location makes system maintenance simple, thereby saving time and costs. More benefits include:

Current isolation between I/O backplane, input circuit, and power supply

The intrinsically safe circuit with dual fault protection provides the highest fault tolerance capability

The I/O circuit provides complete intrinsic safety on-site device protection

These modules are inherently safe and can be installed in harsh environments

The FLEX Ex module can be plugged and unplugged with power. The maintenance and wiring connections of the FLEX Ex network module can be carried out in hazardous areas, and the system is currently operating in harsh environments.